Reeling from her recent breakup, Momo Ayase, a popular high schooler, shows kindness to her socially awkward schoolmate, Ken Takakura, by standing up to his bullies. Ken misunderstands her intentions, believing he has made a new friend who shares his obsession with aliens and UFOs. However, Momo's own eccentric occult beliefs lie in the supernatural realm; she thinks aliens do not exist. A rivalry quickly brews as each becomes determined to prove the other wrong. Despite their initial clash over their opposing beliefs, Momo and Ken form an unexpected but intimate friendship, a bond forged in a series of supernatural battles and bizarre encounters with urban legends and paranormal entities. As both develop unique superhuman abilities, they learn to supplement each other's weaknesses, leading them to wonder if their newfound partnership may be about more than just survival.

A boy and a girl pledge lifelong friendship in a small town junior high school. The relationship between the two, who are destined to share a common dream, has passed two years without any particular development. Himari Inuzuka, a bubbly girl who has yet to find her first love, and Yuu Natsume, a plant-loving boy who enjoys flowers, still spend their days peacefully as best friends in the gardening club in the second year of high school. "If Yuu can't get married, I have to take responsibility." "I'm having trouble now because after Himari said that, your brother began calling me 'My brother-in-law!'" However, when Yuu reunites with his first crush, the gears of their relationship suddenly go out of sync! Will Himari be able to escape her "ideal friend" now that she has found love?

Even as he tries to keep the student council president out of trouble, Vice President Chiga-kun finds himself being drawn to the president's strength and power. Chiga-kun wonders how he, being such an intelligent individual, can be so unwillingly taken with a boy who is so country and simple...