It is the year 2004 AD, and pandemonium breaks as a mysterious frog-like alien race fills the sky with UFOs—or so 12-year-old Fuyuki Hinata dreams. Coincidentally, Sergeant Keroro, leader of a preliminary squad for the Keronian invasion of Pekopon—the alien name for Earth—begins his mission by invading Fuyuki's home. After subduing the boy and his sister, Keroro plans to reunite with his comrades and return to the mothership to repair his invaluable invasion device, the Kero Ball. Unfortunately, he receives word that headquarters has abandoned his unit's retrieval due to an unprecedented issue that forced the rest of the Keronians to flee. Consequently, Keroro is forced to stay at the Hinata residence together with the friendly, starry-eyed Fuyuki; his athletic, short-tempered sister Natsumi; and their hardworking, attractive mother Aki. Now stuck until further notice, Keroro and his platoon spend each day plotting world domination, but are thwarted each and every time by various unexpected factors. Nevertheless, as they live alongside humans, they learn to treat them as friends and allies, forming comedic yet meaningful connections that make their lives on Earth worthwhile.

Kaname Okiura, a student of Prefectoral Umineko Shougyou High (Umishou for short), joined the school's swimming club in order to learn how to swim, but the club is filled with weirdos, let alone who can teach him swimming. Then, a sunny, happy-go-lucky girl named Amuro Ninagawa who transferred from Okinawa joined the club. Her extraordinary underwater speed and unorthodox swimming style (plus her personal habit of nude swimming—a powerful magnet to teenage boys) surprised every club member, especially Okiura, because she reminds him of a mermaid-like creature he saw only once in his early childhood. (Source: ANN)

Sergeant Keroro and his four subordinates came from the planet Keron to the Earth to conquer. However, without notice, they began to enjoy the life on the Earth. Keroro was supposed to stay with Hitana to get the chance to conquer the Earth, but he became friend with Hinata's son, Fuyuki. Today, as usual, Keroro goes to buy his favorite Gundam plastic model with Fuyuki. On their way home, they find a small shrine, and enter. There, they find a vase, and happens to break it. Since the next day, strange things happen all over the town and people are in panic. Inside the vase, Kiruru, Keron's ancient ultimate weapon was sealed. At the moment, Mirara who holds the secret of the Kiruru appears and informs them of the only method to save the Earth. However... (Source: AnimeNfo)

A-gata-kun, B-gata-kun, O-gata-kun, and AB-gata-kun are back again to explore more cultural stereotypes associated with blood type! With assistance from their feminine counterparts, the blood types delve into a range of topics related to relationships, such as one's own charms, how to react to a mediocre gift, and... How to properly hide adult content on a computer? Whether they are stranded on an uninhabited island or sharing a dorm room together, no two blood types will react the same way to any of these humorous yet relatable situations.