Masashi Sakamoto

坂本将志

Akira's tutor before high school. An avid artist, he leaves Hiroko in Japan and travels around the world for his art. It is revealed in the story that Masashi is Akira's half-brother. (Source: Wikipedia) [Spoiler] He is the older brother of Akira and mini-Hiroko (from a different mother) [/Spoiler]