The Hero Alliance travel to the Sakura Cosmos in search of the Top Ten Convicts Number 4 as they are joined by friendship-seeking Shiki Granbell, and Online Video Streamer Rebecca Bluegarden along with her cat companion Happy, join them as they meet many new friends and enemies. Unaware of the trials set ahead for Shiki Granbell.

The Hero Alliance teams up with the Flashy Sound Pillar Uzui Tengan, by investigating multiple disappearances in the Yoshiwara Entertainment District. The foe they may end up facing will be their greatest challenge yet, but there's another also lurking behind the scenes biding their time to strike.