Aimi Tanaka

Umaru is Taihei's little sister who boasts beautiful looks as well as prowess in both school and sports. However, she has a certain secret. She's a "Himôto" a little sister who is proper in public but lazy at home. (ANN)

Kohane Hatoya is a girl who loves to be helpful to others. After she moves from middle school to high school, she becomes fascinated with cheerleading, and she starts a cheerleading club at her high school. Joining Kohane in her cheerleading activities is the experienced Hizume and Kohane's childhood friend Uki. (AnimeNewsNetwork)

Hundreds of years after the 20th century, nature and the ecosystem have been devastated due to use of nuclear and biological weapons. Most of the Earth has been contaminated and is collapsing into ruin, and a great majority of plants and animals are now extinct. The world heads to the "Big Six," the sixth mass extinction event. Humanity built cities in the sky, migrating the endangered species of animals and plants there. Over many years, the animals evolved in these isolated cities.

In the children's room of the Amanogawa household in the neighborhood of Shichifukujin, there are five Engimon: Haruo, Kin-chan (a goldfish paper balloon), Hebikura (a bamboo snake), Chief Daruma, and Koume (a Kokeshi doll). They are always watching over the siblings of the household, Himi and Yamato. One day, an Engimon from somewhere else appears, and Himi leaves the house to chase it. Haruo and his friends come alive, much to Yamato's surprise, and together they go to rescue Himi.