In a near future, an illness called "Cagaster" made ​​its appearance. It turns humans into insects. The story begins 30 years after the onset of the illness, in 2125. It follows the adventures of Kidou, a boy who fights insects.

Deijiko is the princess of the planet of Di Gi Charat. After reading a book, she is influenced to want to help everyone be happy. She leaves the castle and pretends to be a normal girl. She tries to make everyone happy by taking various jobs around the town and thereby making all sorts of new friends and inevitably, enemies.

Leave it to Piyoko! Move over, Di Gi Charat! Piyoko and the Black Gema Gema Gang star in this new OVA series. From the Planet Analogue to Earth, the Black Gema Gema Gang try to kidnap Dejiko and hold her ransom to find their dream of a prosperous home!

Based on the comics by the late Nekojiru. Contains 23 animated shorts aired TV Asahi Network's show "Bokusho Mondai Boss Chara Ou." and 4 unbroadcast episodes.