When Shima nearly drowns trying to retrieve a picture, he’s saved by a merman named Isaki. Despite their differences, they begin to bond, but love across species isn’t simple.

Ayumu, struggling with a rare condition that turns him to stone, creates a new persona for himself, but his feelings grow for his teacher, Kouya, who sees beauty in his transformation.

When unstoppable aliens invade, it seems that all is lost until a teenager with the ability to defeat these invaders appears, but he has no memories of who he is or how to use his power.