After little Yakumo experienced the "Dragon Sealing Incident at Spring Hill," on March 29, 2018, a battleship Hyperion captain named Chen Hua received a mission from Theresa Apocalypse, principal of St. Freya Academy. Captain Chen Hua was instructed to send personnel to Canghai City to investigate and eliminate the hidden Honkai forces there. He decided to ask little Yakumo, captain of the Familiar Incident Investigation Team under the Far East Branch, to take on the mission. But while little Yakumo and her partner Kallen Kaslana were carrying it out, they discovered that there was more to it than met the eye...
