Seki-kun: The Master of Killing Time

My Neighbor Seki (となりの関くん, Tonari no Seki-kun) is a manga series written and illustrated by Takuma Morishige. Originally published as a one-shot in 2010, it started serialization in the November 2010 issue of Media Factory's Comic Flapper magazine. Vertical publishes the manga in North America. An original video animation by Shin-Ei Animation was released bundled with the limited edition of the manga's fifth volume on January 4, 2014, and a 21-episode television series adaptation aired in Japan between January and May 2014.

Plot
These are the observations by Rumi Yokoi of her classmate, Toshinari Seki, as he plays incredibly elaborate games at his desk and somehow never gets caught in the process.

Official

 * Web Site Official

Other Sources

 * Tonari no Seki-kun on Wikipedia