After a routine beating at the hands of Kirie, Yukinari falls into his bathtub and disappears. Afterwards, he meets Miharu and discovers Seiren–a world near Earth with a 90% female population and a craving for men.

Enticed by the thought of spicy curry bread, Miharu ventures outside to find Yukinari's school and buy some, instead of waiting for him to come back. Along the way, she discovers the shopping district–and bananas.

Inspired by her daily horoscope, Kazuharu's sister, Lisa, kidnaps Yukinari and tries to marry him after a chance encounter on the way to school.

An amnesiac Koyomi arrives from Seiren; and after some recollection, she remembers her mission of finding Miharu and return her home.

Koyomi observes Miharu's time on Earth. Despite her decision to return to Seiren alone, Miharu joins her. After a brief Seiren stay, Maharu allows Miharu to return to Earth, along with Tomoka and Koyomi.

Koyomi is given the task of finding a husband for Maharu and struggles with her androphobia. Tomoka competitively takes on that same task.

Miharu consumes an unknown liquid in chemistry class, and inadvertently creates a swarm of Miharu clones. Local shop keepers are then left to defend themselves from the clones insatiable appetite.

Tomoka and Lisa fight over the human-form Ebi. Lisa is then reminded about her magically animate doll friend.

Yukinari and friends travel to a hot springs resort. There, they find a female spirit unable to leave Earth and work together to help her move on to the afterlife.

After the Fukuyama siblings buy out various hot spring resorts, a ping pong challenge between Kazuharu and Koyomi wages a bet involving Kirie.