The story centers around Ryouta Yonekura, a young man whose motto was "Don't be wasteful." While touring an environmental organization, he comes across the base of a mysterious group called the Kankyou Hogotai Mottai 9. Led by a beautiful woman, the team has vast resources at its disposal such as a giant robot. Ryouta decides to get acquainted with this team in order to show them the true path of not being wasteful.

Brad Lester, once renowned as the strongest mage, vanished from the public eye after the tragic death of his young daughter. While living a quiet life as a lowly day laborer, his beloved wife is murdered by the "World Peace Promotion Association," an organization seeking his power. Driven by a despairing rage after losing everything, Brad sets out for revenge—only to find Valburga, the leader of the Association, has been transformed into a little girl!? Furthermore, she has lost her memories and has nowhere to go. Haunted by the memories of his late daughter, Brad resolves to "help his arch-nemesis regain her memories." Visiting the Olford Ancient Magic Research Institute, the mouse-worshipping town of Brooke, and the blizzard-shrouded village of Lutz, their long journey across the land begins—. An adventure fantasy of the strongest mage and his "child" companion!!

A collection of short, comedic stories from early in Yagami's career.

Collections of one-shots that won the monthly Hop Step Award from 1987 to 1996.

Anthology of D.Gray-man doujinshi written by different artists. Pairings: Allen x Kanda, Kanda x Allen

Pairings: Kanda x Allen, Allen x Kanda

Anthology of doujinshi from different artists. Cover illustrator: REIMON Peine Colour illustrator: Takahira