Harried by insurgent forces and their own guilt, Rousei and Itecho make for the four-season's agency building to rescue the Agent of Spring. There, Lady Hinagiku and her guard, Sakura, have dug in on the upper floors to fend off an assault of their own! But their battle has only begun, because the mastermind behind the kidnapping of the Agent of Autumn, Nadeshiko, has just arrived...