Tsutomu, an ordinary middle school student, preoccupied with studying for his high school entrance exams, becomes entangled in a pursuit when he encounters a man fleeing from an unknown assailant. Amidst the chaos, he is unwittingly slain. However, Birdy, a space agent, possesses the ability to revive him. The caveat: they must merge into a singular entity. Despite his reservations, Tsutomu is now amalgamated with Birdy and embarks on a mission to apprehend wrongdoers and avert tragedies.