Daruku Hoshino 星埜 ダルク

He is Tensai's assistant, where they maintain a sort of Sherlock Holmes and John Watson-like relationship. Though he may look like a girl, he is actually a cross-dressing boy. Daruku, along with Tensai, transfer into Juugo's school where they are also the his classmates after their brief visitation at the his apartment where they also met Nanana. He also becomes a member of the "Adventure Club" since he goes wherever Tensai goes.