Chocotto Sister (ちょこッとSister, Chocotto Sister?) is an ongoing manga series written by Go Zappa and illustrated by Sakura Takeuchi. It is published by Hakusensha in the magazine Young Animal and collected in 8 tankōbon volumes to date. The series has been adapted as an 24-episode anime by Nomad, airing in 2006 and released on 8 DVDs. It is also known as Chokotto Sister and Chocosis.

Source: Wikipedia