By day, Romeo Maki is a respectable man who loves bringing gifts to the local orphanage, and Juliet is a newly employed nun working at said orphanage. However, by night, they are Masked Man M and Lady S, popular professional wrestlers. Kick-Heart tells the story of what happens when this dynamic pair meet in the ring, the only place where they can express their hidden desires.

2035 A.D. The heads of ancient giant idols were excavated all over the world. Using those twelve stones statues, Humanity had barely overcome the threat of extinction called the "Equatorial Winter". But the stone statues had forced Humanity to construct colossal suits of armor as their bodies and demanded that the humans fight each other. (Source: ANN)

When Ryuu is born his tribe tries to sacrifice him to a Tyrannosaurus named Shirano because of the color of his skin. He is however saved by a monkey who raises him as her own son. Meanwhile Ryuu's mother has left the tribe and is out on a quest to find Ryuu. 16 years later Ryuu meets a girl named Ran who was sold to the tribe Ryuu originaly came from. The tribe is not happy to see Ryuu alive and tries to sacrifice him again, this time by burning him alive. Before they can get the deed done the tribe is massacred along with Ryuu's adoptive mother by Shirano. Ryuu then sets out on a quest together with Ran to find his mother and Ran's brother Don.

Tie-in anime linked to the "Idol Land PriPara" smartphone game.