The city of Binan in Japan is home to the Earth Defense Club, a club at Binan High School that was notoriously inactive. During a relaxing soak in the hot tubs at Kurotamayu bathhouse, two club members named Atsushi Kinugawa and En Yufuin were unexpectedly visited by a pink creature named Wombat who materialized out of nowhere. Wombat implored Kinugawa and Yufuin for assistance in saving the planet with the power of love. Unimpressed by Wombat's appeal, Kinugawa and Yufuin were soon joined by Yumoto Hakone, son of the bathhouse owner, who enthusiastically chased after the strange creature while shouting, "Let me fluff you up!"
The following day, Kinugawa, Yufuin, and their fellow club members Io Naruko and Ryu Zaou were ambushed by Wombat at school, and bracelets were attached to their wrists with commands to save the earth. A mysterious and bright light emerged from the bracelets, enveloping the group and transforming them into the "Battle Lovers," the inheritors of the throne of love. As the transformation occurred, they heard the words, "It's about love-making!" echoing in their minds.
