Riku jumps off to reunite with Sachino in the afterlife, whom he had been in love with for a long time. When he wakes up, he finds a mysterious wizard standing there. The manga illustrated by zinbei, related to the album HappyEND by HoneyComeBear. Each chapter occurs with the song and music video of the same name, with 10 songs and 10 main chapters taking place over a period of 10 days, each music video releasing on the day of event from August 1st, 2021 (Sunday) to August 10th (Tuesday) telling the story of Riku and Sachino.