Buso Renkin: You've Become A Little Stronger

Muto Kazuki and Tsumura Tokiko are investigating who is behind all the homunculi appearances and hostile acts. Only with two leads: He wears a Papillion Mask and attends Kazuki’s high school. With that in mind, Kazuki and Tokiko do a thorough search of the high school–searching for more leads as to who this mysterious ” Papillion Mask Creator ” is.