He is a friend of Kusuda. Sogabe is a bit of a delusional character, as well as a little narcissistic. He likes Nao and tries to get close to her to create an opportunity for her to confess to him. He shows his insecurities when Nao shows interest towards Yukito Renjou, an artist and graduated student from their school. He runs away from home because of this (although only for two days) with Kusuda and Mamoru. After he loudly admits his feelings towards Nao such that she hears it (after she and the other girls pursue the runaways), the two become close. Near the end of the series, he cuts his hair.