Tetsuya is Keisuke's best friend, they attend college together. Tetsuya becomes involved when he runs into Keisuke at the library. At first he doesn't believe Keisuke's story about his little sister going into a book, but eventually believes and helps in anyway possible. Near the end of the tv series and in the OVAs, Tetsuya voices a fervent wish to enter the book world, he also eventually develops a crush on Yui.