Manga / Recorder and Randsell

Atsushi(left) and Atsumi(right)

Atsushi Miyagawa is an elementary student who looks like an adult. His older sister Atsumi is a high school student who looks his age. Since they act like you'd expect kids their real ages to act, this can cause... problems.

Recorder and Randsell is a yonkoma that was adapted into a three-minute anime that began airing in January 2012 and was licensed for simulcast by Crunchyroll.

A third season aired as a part of the Summer 2013 Anime season.

And if you're wondering, "randsell" refers to the type of backpack Atsushi's wearing.

This series displays the following tropes: