Tadashi is a fairly young, spectacled teacher. He has dark brown hair, noticeably dark eyebrows, and brown eyes of a slightly lighter shade of his hair. He is primarily seen in a white shirt with a pink vest over it, along with a red tie.
The teacher is shown to be very energetic with his lessons, and often speaks excitedly when mentioning his beloved wife Juko Yagi—an occurrence that comes along frequently. Around his wife, he is shown to be extremely happy.