Исахая Тэнко

Isahaya is the grandson of a rich business owner whom Iruma borrowed money from. He likes playing with Iruma's son, Masashi, and has a toy bear named Maa-kun that's actually a very complex robot. While his grandfather spoils him a lot and keeps him isolated for his own safety (mostly from relatives who want to kidnap him for ransom), Isahaya would much rather go out and make friends.