Butler of Aiba family and cares about Ruri Ojou-sama. He graduated from Harvard University at his young age, but enrolls in the high school as Ruri and Alma to support Ruri, who is in need of Alma's power. He also fights against the evil stones by riding "Engagement Suite" (Robot), and is jealous of Alma for having the stone's power.

Spoiler

He fell in love with Ruri when they were younger.