Mochizō Ōji (大路 もち蔵 Ōji Mochizō) is Tamako's childhood friend whose family runs Ōji-ya, a mochi shop located across from Tama-ya. Though their fathers are not on good terms due to business competition, he and Tamako are good friends. He is in love with Tamako. 
Mochizō is a young boy in his mid-teens. He is fairly tall, measuring a few inches ahead of Tamako. He has light brown, chin-length hair. One strand of hair hangs in the middle of his face between his brown eyes.
Mochizō wears his school's uniform that is a dark blue, formal suit with golden buttons with a white shirt and a light green tie. His tie tends to be loose, with the collar of his shirt opened slightly. At home, he often switches to his regular clothes, consisting of different sweaters and shirts. He also has a black stud piercing on his left ear.
A kind-hearted soul, Mochizō will go out of his way to help anyone, especially Tamako. He often acts shy and timid around her, not being able to release his true feelings, and has a habit of touching his face when praised or embarrassed. He has a habit of speaking before thinking, not realizing Tamako has left his peripheral vision before doing so.
As a child, he was less conscious of what he said and often teased Tamako to hide his crush on her. Over time, this personality faded away and he became more compassionate around Tamako most particularly after her mother's death.
At school, though he was remarked by some female students to be a bit of a nerd due to his film society's antics, he seems to be popular among girls in his third year of high school, having been confessed to by an unknown girl.
Born to mochi shop owners Michiko and Gohei, he had been with Tamako since they were infants. He often teased Tamako for being a daughter of a mochi shop owner despite its hypocrisy, calling her a mochi shop's dumpling, but this was noted by Tamako's mother his way of hiding his crush on her. He often held one of her pigtails as they walked.
Mochizō was present at the funeral of Tamako's mother. At some point, he consoled Tamako by putting a face on mochi, reassuring her that her mother was in a better place. It was considered this to be the point where he behaved less of a bully to her and became much kinder.
At some point, Michiko came up with the idea of the paper cup telephone line because Tamako's father was bothered at night by the constant noise Mochizō and Tamako would be causing by yelling to each other. This habit would continue from their childhood to their present teenage years, despite others' comments that they should become more modern with cellphones.
Mochizō is first seen witnessing his father and Mamedai have a dispute over the former's new sign title for his mochi shop exasperatedly. Upon Tamako approaching him, he seems to perk up and smile, greeting her. He confuses the bird on her head as a hat. When the bird falls off of Tamako's head, he assists in lifting the bird inside Tama-ya. In there, Tamako's father Mamedai accuses Mochizō of spying to which he frantically apologizes. Mochizō watches in a mixed reaction of horror and shock as the bird begins to speak, introducing himself as a royal bird named Dera from the Mochimazzi family who has come to find a bride, and he suggests to Tamako to just throw the flamboyant bird out. When Mamedai tosses the bird to the other side of the room, he addresses Mamedai as "Father" and is promptly scolded.
He is later seen leaving the public bathhouse when Tamako and her younger sister, Anko, arrive. Despite already having bathed, he lies as an excuse to stay with Tamako longer. He meets up with the bird and takes the bird inside, all the while trying to conceal Dera's identity as a talking bird. Seeing Dera attempt to peek in on Tamako and Anko by flying to the girl's side of the changing room, Mochizō quickly warns Tamako and this thwarts Dera's attempt as he is tossed back on the male's side. When New Year's approaches, it is revealed Mochizō has been unable to deliver a birthday present for Tamako due to incidental circumstances beyond his control and his shyness. While sleeping, he appears to be dreaming about Tamako while Dera is slapping him with his feathered wings. Asleep, he asks for "Tamako" to go for the other side as well, to which Dera violently slaps him more and asks if Mochizō is a pervert. When he reaches Tamako's house, he is told that someone is choking and he instantly goes to smack Tamako's back in the widespread assumption that she is the one who is choking, when in reality it was Dera. In all the commotion, he — including the rest of the Usagiyama shop owners — forget to deliver their birthday presents to Tamako.
As Valentine's Day approaches, Mochizō wakes up from a nap to Tamako clapping across from his house upstairs to direct his attention, gesturing for him to take out the cup phones. He is initially unable to hear Tamako's communication through the cup phones, as Dera is standing on the strings that attach the two's cups. He learns that Tamako desires to liven up the market and he agrees to come along with her to the next Usagiyama meeting. There, it's revealed that both him and Tamako as well as the bathhouse owner have a tendency of stuttering when delivering a speech, and he once again addresses Mamedai as "father" when he attempts to calm down his and Gohei's argument. Mochizō offers to create a commercial for Usagiyama, as he's in the film research society at school, to support Tamako putting up a Valentine's Day theme for the shopping district.
During filming, he gently chides for Tamako to act more naturally for the commercial, to which she jokes that she'll pound him up into mochi. They do manage filming, and when showcasing the commercial, Mochizō and the others discover Dera's beak has the capability of being a video projector.
When a new school year arrives, Mochizō is shown to be in the company with his two unnamed friends, a short boy with glasses and a taller boy with glasses. He is disappointed that he, once again, he is not in the same class with Tamako who is in 2-A. He does, however, have the same class with Midori Tokiwa in 2-B.
Mochizō has a major appearance in Episode 5, where he decides to confess to Tamako once and for all with Dera's convincing. It is the summer, and he is shown lazying around in the front fanning himself. He is scolded by his father, and is asked to at least to work besides sit around. He watches as Tamako and her two friends, Midori and Kanna leave her house before Tamako notices him and offers if he wants to come along to the pool with them. He declines, however, without relevance to Midori's comment that he is a boy and therefore cannot come along as they will be wearing swimsuits. Mochizō's mother smacks him with a rolled up magazine, telling him to start on his homework. Mochizō is later seen regretting his declination to the invitation, and imagines that even if he went, he'd just behave in a reserved manner with Tamako. Dera notes this as well, having known that fantasy due to the fact Mochizō was speaking aloud. Dera finds out Mochizō has a crush on Tamako, and urges him to confess.
At the field trip, he brings along Dera to assist him on his confession. This attempt is thwarted, as Midori interferes out of concern for Tamako. He is confused, but Midori later tells him that Tamako would just think of him as a stalker. He responds by surely Tamako likes him more than Midori, pointing out that his name as "mochi" in it, the food she loves so much, and has known her longer to know that Tamako once wore large glasses before getting contacts, though Midori retaliates by telling him that Tamako can swim more meters now to which he is surprised. During the fireworks performance, Midori tells him that he may confess to Tamako, but he declines. He later advertises his family's mochi shop, mimicking Tamako, and the tension seems to have decreased between him and Midori. When Choi Mochimazzi comes to Usagiyama Shopping District, he comes along with the rest of the residents to see her. He tearfully says she's brave, for her age, to come so far. Choi tells a prediction of the "Great White Maw"'s arrival, which is revealed to actually be a large white dog that comes rushing past them while being chased by its owner. He mutually is in awe with Tamako at the revelation.
After seeing Sayuri's love fortune in regards to her marriage, Mochizō shyly asks Tamako if she happens to be thinking of marriage herself. To his disappointment, he finds that she didn't hear him and has already wandered towards the group. He is shown sulking in the background.
Before Mochi Day (as well as his birthday), he comes up to Anko on the way home from school and asks if Tamako has any plans for his birthday. To his dejection, Anko answers that to her knowledge, Tamako has forgotten due to plans for Mochi Day. As Anko seems unhappy, Mochizō assumes that it's because of his situation, to which she sharply tells him that it isn't because of him.
That night, he converses with Tamako over the cup phones about Anko, as Tamako is concerned over her sister's temperament as of late. He offers to confront Anko about it, and smiles as Tamako thanks him.
The following morning on Mochi Day, he keeps to his offer and comes to see her in the morning. He repeatedly gets what she's upset over incorrectly and eventually she snaps that her friend, Yuzuki, is transferring schools.
Mochizō assists in the competition that his father is having against Tamako's father Mamedai for Mochi Day. However, as his father turns to face his own building, it's revealed that Mochizō is at Tama-ya, much to both of the men's anger. While making mochi, he explains why Anko seems depressed to Tamako.He later leaves from the group while the mochi is being made to speak to Anko, recommending that she should go see Yuzuki before he leaves to say goodbye, going so as far as to suggest her to tell him that she loves him seeing her being conflicted over what to say. Tamako comes up to both of them with a bag with freshly-made mochi and tells Anko to deliver them to Yuzuki as a base for conversation. After Anko departs, Tamako thanks Mochizō.
That night, Mochizō plays from the projector an old video of Mamedai performing with his band a song that was composed for Hinako, Tamako's mother, in high school. He remarks positively on the band. Following the viewing, Tamako surprises Mochizō with a birthday cake and reveals that she hasn't forgotten. Overwhelmed with relief, he ends up weeping. 
For their high school's culture festival, Mochizō's film society club ends up being the first to be presented due to a drawing, with their creation revealed to be a comedic kung-fu film. In the film, Mochizō had to leap into a pond to catch a turtle, causing him to be reprimanded by a school staff member.
He calls Tamako on the cup phone that night, appearing to have caught a cold from the pond incident. Although the crowd won't be very attentive with the film being shown first thing in the morning, he seems to be at ease with it. Despite his cold, he confirms that he'll still be filming Tamako's baton club performance (and remarking silently that he's specifically filming Tamako). He keeps his words (and the ones he did not utter).
When Mochizō learns that Tamako may be the bride to an island prince to his horror, he immediately confronts her about it the following morning. As she converses with the prince with Dera's projector, he appears sullen. Afterward, he privately talks to Tamako about the marriage over the cup phones. The moment Tamako opens her window, he impulsively tosses the cup phone over to Tamako and accidentally hits her in the forehead. Mochizō tells her that he'll be fine with any decision she'll make so as long as she's happy.
The next morning, he finds that Tamako is upset that she's lost her medal from her loyalty points in the shopping district. He offers to give her the loyalty points he's collected over time, although she declines. A boy extends his hand holding her medal, asking if it's what she's searching for, who is revealed to be Mecha Mocchimazzi.
On the way to school, he runs up to Anko and Tamako, appearing to have lost sleep over the prince's arrival for Tamako. When Anko says the prince is here to pick Tamako up to take her to the island, Mochizō is shocked but quickly asserts that he's fine with whatever so as long Tamako's true to her own feelings, to which Tamako retorts that he doesn't look like he is.
Tamako announces that evening that she doesn't quite want to leave, having grown long fond of the shopping district that she's grown up in. She mentions Mochizō and their cup phone conversations as one of her fondest memories, having done so initially because her father had been angry over Mochizō and Tamako speaking late at night. Michiko, Mochizō's mother, had given them the cup phones so they may talk in secret. It's revealed that Tamako isn't the bride of the prince, as Choi had only wished for a proper bride for him and felt that Tamako's personality was fitting.
He sighs in relief alongside Midori.
As Tamako's birthday comes around again, Mochizō decides to gift her with flowers from Kaoru's flower shop. Without his knowledge, Dera is in the bundle of flowers, although Tamako seems to be gleeful finding him.
Tamako Love Story Edit
Anko's Diary Edit
In a short story published by Mutsuki Ichinose narrated by Anko, she records the rainy day that occurred where the new couple Tamako and Mochizō share an umbrella in the rain.
It's remarked that while Tamako seems happy per usual, Mochizō appears embarrassed as they come inside. As Mamedai and Tamako's grandfather are absent due to their own plans, Anko has to look after the store herself. Mochizō offers to help if she needs any, referring to himself as Anko's big brother-in-law. Hearing Anko's confusion, Mochizō corrects himself that he'll assist with any big luggage.
Mochizō returns to his family's mochi shop, pointing out he'll probably be in trouble if he doesn't.
Tamako later texts him an accidental draft that she never deleted that was written by Kanna, asking him to build a house for her. He runs outside in the rain to Tama-ya, professing for her to give him five—then insisting three—years for him to build a house for her. After the situation was explained, Anko asks him to pay upfront for mochi, as he's a customer for entering the shop.
Later, Tamako thanks him via text for the fun day, to which he responds he had fun as well.
Aside from being in a mochi-associated business, he is proficient with the camera, often recording scenes for the school. He actively participates in his school's film society club. Because of this, he plans to attend a university in Tokyo.
- Tamako Kitashirakawa: Mochizō and Tamako have been together since they were infants, due to their mothers being friends. As a child, he often behaved in an insensitive manner, calling her a dumpling. Following Tamako's mother's death, he would often console her and lend her an ear when she was upset. He comes to terms he is in love with Tamako, but this causes him to be nervous around her. When she had given him a birthday cake, he was reduced to tears, having thought she'd forgotten. He refers to her father as "dad" despite the latter's rejections, implying he wishes to marry her one day, and this is hinted once again when he asks of her thoughts on marriage. When she was being allegedly married to a foreign prince, Mochizō had noticeable dark circles under his eyes due to lack of sleep, despite him insisting that Tamako should do what makes her happy. In their final year of high school, he confesses to her at the riverbank. He was visibly upset at the prospect of Tamako not actually loving him back. She, however, later tells him she returns his feelings at the train station after some time thinking, and they are seen standing together at the credits of Tamako Love Story..
They we're a sweet couple. 
- Midori Tokiwa: Initially on bad terms due to Midori's possessiveness over Tamako, the tension between the two was lessened at the end of the day. Mochizō, though not expressing hatred towards her, seemed merely confused with her behavior. They are shown to be not very close, as they address each other by their surnames. She on the other hand had a sharp tongue towards him, believing that Tamako would think of him as a stalker. They are both shown to be relieved when finding out Tamako wasn't leaving, both mutually smiling at each other, indicating any tension has been resolved mostly. Later in their third year, she demands to know when he will confess to Tamako. Finding out he has confessed to her and she returns his feelings, Midori is saddened but accepts this, wishing the best for Tamako's happiness.
- Anko Kitashirakawa: They are on friendly terms, with Anko nicknaming him "Mochi". They have a signature greeting when seeing each other by raising a hand and not waving it. She appears to trust him enough to confess her worries, and she had expressed concern when he appeared to be distressed on the way to school, similar to the former in previous situations. Around each other, Anko acts as the more rational person; because Anko has seen him in many embarrassing situations, he can never hold his head high around her.
- Mamedai Kitashirakawa: At first, Mochizō's comfort in his presence seems one-sided. Mamedai often regards him as a spy, only coming to their shop to leech off of their recipes. Mochizō frequently calls him "dad", much to the latter's irritation. Nevertheless, this tension seems to be slightly resolved when Mamedai mentions Mochizō's father's distress regarding the teenager's plans to attend a university in Tokyo.
- (To Tamako) "I . . . No matter where you go, no matter who you're with, I'm fine so as long as you're happy. Not just me, but everyone in the shopping district thinks so, too."
- (Referring to Tamako) "That's right, I'm just worried. You know how she's always spacing out or doing something reckless, right? I worry about her, so I can't leave her alone."
- "Tamako. I'm in love with you. I'm madly in love with you!"
- His birthday is on Mochi Day, October 10 and curiously, the same day of Tamako Love Story's BD/DVD release.
- His blood type is B.
- ↑ 1.0 1.1 1.2 1.3 1.4 Tamako Market anime, Episode 5.
- ↑ 2.0 2.1 2.2 2.3 Tamako Market anime, Episode 7.
- ↑ 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 Tamako Love Story film, 2014.
- ↑ 4.0 4.1 4.2 Tamako Market anime, Episode 10.
- ↑ 5.0 5.1 5.2 5.3 Tamako Market anime, Episode 1.
- ↑ 6.0 6.1 Tamako Market anime, Episode 2.
- ↑ Tamako Market anime, Episode 3.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 Tamako Market anime, Episode 9.
- ↑ 9.0 9.1 9.2 Tamako Market anime, Episode 11.
- ↑ 10.0 10.1 10.2 10.3 Tamako Market anime, Episode 12.
- ↑ 11.0 11.1 11.2 11.3 11.4 Tamako Guidebook: Anko's Lovey Dovey Diary
- ↑ Tamako Love Story Guidebook (Reiko Yoshida)
- ↑ Tamako Market Official Art Book.