On his way home from school, Tatsumi sees a man collapsed near a lake. When he approaches him, Tatsumi notices something strange: the person in need of help is actually a beautiful merman named Wakasa! Because Wakasa's home has become too polluted to live in, Tatsumi graciously offers his bathtub as a refuge. With a boisterous merman as his new roommate, Tatsumi's normal life won't be returning anytime soon, not to mention Wakasa's aquatic friends—Takasu, Mikuni, and Maki—often show up uninvited, making them all quite a handful for the high school student. As he humors their curiosity for human life, Tatsumi sometimes finds himself enjoying their childish antics, but he will have to keep his cool if he intends to keep up with his daily life and newfound friendship. [Written by MAL Rewrite]

Leona Ozaki joins Newport City's infamous Tank Police division. With aid of Al and her newly built mini-tank, Bonaparte, she wages war on Buaku and his cohorts, the Puma Sisters.

The five digi-destined children stumble upon an ancient island inhabited by two different types of digimon; The Beast types, and the Human types. When they see two young digimon-a beast and humanoid-have become friends, they decide something must be done about the feud.

(Source: ANN)

The film's story begins when Shiriri, an alien, arrives and turns Hiroshi and Misae into children. To turn them back, Shinnosuke must travel the length of Japan with Shiriri hidden in his butt. Meanwhile, Shiriri's father is moving forward with a huge conspiracy. 

(Source: ANN)