Recorder and Ransell

Recorder and Ransell is a yonkoma manga series by Meme Higashiya. It follows the lives of two siblings; Atsushi Miyagawa, an elementary school boy with the appearance of an adult, and Atsumi Miyagawa, a high school girl with the appearance of a young child. They live everyday encountering misunderstandings and misadventures, most to be blamed to their ironic age/looks.

An anime adaptation by Seven aired from January 5, 2012 to June 27, 2012, with another season to air in July 2013. The seasons were titled Recorder to Ransel Do, Recorder to Ransel Re, and now Recorder to Ransel Mi, respectively.