一座平凡的高中，某间教室内鸦雀无声。一脸严肃的老师在讲台上专心讲课，学生们埋头伏案，奋笔疾书。不过坐在最后一排的两个人却似乎有些异样。名叫关俊成的男孩时常开小差，在自己的一方领域里或者玩骨牌、或者造富士山、或者烫衣服、或者做泥塑，总之脑洞大开，各种搞怪 杂耍不断。而他的小动作不可避免影响了坐在右手边的横井留美。原本专心上课的留美三不五时被关同学所吸引，她不知不觉投入其中，乐而忘返。另一个故事中，新转学而来的郁野留美操着一口方言，经常做一些搞怪大条的事情，令她的同桌和老师几近崩溃…

The boy who sits next to Yokoi in class, Seki-kun, is always up to something at his desk. He manages to somehow play very elaborate games without attracting the teacher's attention. From dominos, to shogi, to go, to mecha models, to playing with cats and more, he always has something new to do. Yokoi often finds herself getting reluctantly interested in his games, even though they always seem to end up getting HER in trouble with the teacher!

「옆자리 세키군」, 「루미짱의 사상」 등 두 만화 작품을 원작으로 한 드라마. 수업 시간의 책상 위에서 다양한 놀이를 즐기는 세키군과 취미 및 특기가 '탈구'인 루미짱의 이야기를 그려낸다.