In the near future, after a nuclear explosion has caused the Earth to collide with Hell, elementary student Kento finds a small daemon creature named Anna and raises her. The series follows the adventures of Kento and Anna as they embark on a journey to rescue his mother.

The original video anime episode will serve as the final chapter to the television series, focusing on the rivalry between the "background character" Amatsuyu Kisaragi (Jouro) and Yasuo Hazuki (Hose), "the protagonist."

It is Tetsuya Kuroko's birthday. In celebration, Satsuki Momoi has invited the other members of the Generation of Miracles to play basketball together and rekindle the memories from their nostalgic middle school days. Meanwhile, Taiga Kagami and his fellow teammates of Seirin High are doing their best to prepare for Kuroko's birthday party. Sometimes, the best gift one can receive is not a material one but, rather, the feeling of having fun with everyone!

In a fateful childhood encounter, Mira Kinohata met a stargazing dreamer named Ao Manaka. Though their time together was short, Ao showed Mira the wonders of astronomy, from orbiting planets to distant stars. Before they parted, Mira learned that a star with her name exists, but there are none with Ao's. And so, she forged a promise: one day, she would discover a new asteroid and name it after Ao. Years later, Mira is still fascinated with astronomy. Now in high school at Hoshizaki Academy, she tries to join the Astronomy Club. Unfortunately, she finds out that the club has been merged with the Geology Club to form a single Earth Sciences Club. She joins this new club and finds a pleasant surprise—she reunites with Ao after years of separation. Alongside their new clubmates, Mira and Ao begin their journey together to fulfill their promise. How hard could it possibly be to find an asteroid? [Written by MAL Rewrite]