Cyborg's functions are suddenly malfunctioning, so they need to search for the cause.

A year after the final battle, the four girls, Mana, Rikka, Makoto, and Alice had fully returned to their normal lives. Regina, who had entered the same junior high school as Mana and Rikka, is just as boisterous as ever, but Aguri also enjoys spending time with them, making for peaceful days. Then one day, the Jikochuu, who were supposed to be left behind in that decisive battle, suddenly appear again....! The final summer of junior high for Mana and her friends features another decisive battle. The heart-pounding has yet to stop!