When a mysterious creature with the appearance similar to a Wombat came to this world out of seemngly nowhere, the 5 boys from the Earth Defense Club were chosen to protect this Earth from the Loveless and spread love to all by becoming Heirs to the Throne of Love.
Wombat gave each one of them a Loveracelet, which would light up if the Loveless were nearby, so the Princes could then go and deal with them.
Each Prince has a different Transformation when they kiss their Loveracelets, and they each become a different Battle Lover.
Each Prince has a different coloured Love Stick hidden in the heart shaped jewel on their bows, and they can summon them by reaching into their hypothetical hearts.
Each Prince has a different coloured and powerful Beam that comes out of the Love Stick when they point the stick and shout random names.
The Princes can join their Love Sticks together to create a massive staff that is wielded by Yumoto, which they can use to do the Love Attack finishing move on the Loveless.
Yumoto can once again wield the massive staff to perform Love Shower, to cleanse the Loveless and fill them with Love, as if they've been showered in it.