Prepare for a full dive! After their battle with the Acceleration Research Society, Kuroyukihime and the other members of Nega Nebulus have finally resolved to face the White Legion, Oscillatory Universe! To have a fighting chance against White Cosmos, Nega Nebulus knows that forming an alliance with the Green Legion is paramount. So after scheduling peace talks with the Green Legion's Master, Green Grandé, Haruyuki travels to their home base, located in the Shibuya Ward. But when he arrives, he discovers that the one awaiting him is none other than...Kuroyukihime in a swimsuit?!