The city of Binan, somewhere in northern Kanto.
The five members of the Binan High School Defense Club (Hakone Yumoto, Yufuin En, Kinugawa Atsushi, Naruko Io, Zaou Ryuu) ended up having to "Love Making" (transform) into the Battle Lovers to fight against monsters.

The monsters were humans transformed by the student council (Kusatsu Kinshiro, Arima Ibushi, Gero Akoya), also known as the villainous Caerula Adamas. After a long fight, the mastermind pulling the strings was defeated, and the Earth Defense and Conquest Club reached a peace agreement. But not long after things were resolved, a new, mysterious enemy appeared: Galaxy Idols, the VEPPer.

While they fought the monsters, the Defense Club visited the beach, Mt. Binan, the school culture festival, and the amusement park; they celebrated Christmas, New Year's, and Valentine's Day, and generally enjoyed their high school lives. But the next thing they knew, the year had passed them by.

Now it's March, and graduation is imminent. Both the graduating third-years and the remaining second- and first-years find themselves facing complex feelings they can't quite put into words...

[Source: Crunchyroll]