Papa's Assasin. - Ryuunosuke wa Tonde Yuku.

Ryuunosuke, a high school student, lives with his annoyingly popular father, Daniel. Though Ryuunosuke is unaware of this, he was actually handed off to Daniel when he was three years old by a random woman. Ryuunosuke has several good friends and in general spends his day happily, but he has a Secret that he's keeping from Daniel... What could it be?