OVA bundled with 4th volume of manga.

A collaboration between Blue Exorcist and Kakko Kawaii Sengen.

The battle against Tendou Kodzunu is over, and the Magami Five begin to look forward to their senior graduation, hopefully planning for their adult futures. However, life in Tokyo is not at peace... The underground assassin group known as the Twelve Heavenly Generals of the Martial Fist begin to move against those protecting the city from demons. Normally rumored to kill criminals that the mundane law was unable to bring to justice, the Martial Fist now set their sights on Tatsuma Hiyuu, Kyouichi Houraiji, Aoi Misato, Komaki Sakurai, Yuuya Daigo, and Hisui Kisaragi. What is the purpose of this cruel turn of events? And who ordered the hit? New threats emerge as others awakened to powers unleashed by the Ryumyaku seek out the Magami kids - and old friends now return as enemies. Destinies will collide as the Stars of Fate begin to merge; Yin and Yang will meet. And soon the shadowy figure pulling the strings will reveal himself, in an effort to raze Tokyo to the ground and awaken the Vessel of the Golden Dragon.

Pandy and Retro awaken naked on Earth with no recollection of their past. They embark on a devastating crime spree in search of food, clothing and transportation, but are captured by authorities and sent to the infamous lunar penitentiary named Dead Leaves. While incarcerated, they quickly discover that Dead Leaves is also a top-secret cloning facility, occupied by villainous guards and deformed genetic experiments. Ultra-manic chaos and hyper-violent bedlam ensue as they organize a prison break with the aid of their fellow mutant inmates.