Shinobu is Akira's older brother who attends university. He is constantly worried about his sister, and often takes her places in his car, though Akira often gets very annoyed at how protective her brother is towards her. He is often seen giving up a lot of his free time following her around, much to the chagrin of both his sister and mother. He is often told by his mother that he needs to get his own life in order before he could be concerned about his sister's life. He however claims that his overprotective nature is not as bad as their father's. Despite forcefully volunteering to chaperone Akira and her friends around, he is exasperated by them. He finds the group of girls to be tiresome, save for Fumi, who is not as exicitable as the rest. He eventually comes to find out that Fumi is a lesbian through a conversation he has with Yasuko, which surprises him. He shows interest in Kyouko, though mostly out of curiousity rather than attraction. Shinobu is a little gruff with any males he sees interacting with Akira. He suspects Sawanoi Kou of having designs on Akira and so keeps an open eye on him. Shinobu eventually starts dating Miwa "Mogi" Motegi, Fumi's schoolmate.