Taishi has short, messy grey hair and turquoise eyes. Taishi is most often seen in his middle school uniform. In the anime it is shown as a white collared shirt and grey pants.
He is described as a typical middle school student. He is polite and can communicate well. Hachiman's first impression was of "a boy with good prospects - although he's still not good enough for Komachi".
Taishi is a caring brother and worries about his older sister Saki, and 2 younger siblings a lot. He is very trusting as he asks Komachi (a new friend) and by extension, Hachiman for help with something very personal. He is very enthusiastic while working with Hachiman and demonstrates his desire to help when he can.
He is shown to be timid, but has a slightly perverted side since he worries that his older sister working in place named "Angel-something". He also compares class 2-J that consists 90% of girls to paradise, indicating his young mind interest on girls.
He is pretty smart as he is trying to get into Sobu High for his high school. He even asks Hachiman for help with the school entrance exam tips.
- He was shown only in season1 and not in the sequel of the series.
- He is one of the few to have Hachiman's contact ID through Komachi.