Eiken (エイケン) is a Japanese manga series written and illustrated by Seiji Matsuyama. The story depicts the life of schoolboy Densuke Mifune after he is forced into the mysterious Eiken Club. The manga series ran for eighteen volumes, and additionally included a series guidebook. A number of radio drama episodes and a two episode OVA (the latter roughly based on a volume 3 storyline) have also been produced. The first twelve manga volumes have been released in North America. The first three volumes were rated 16+, while subsequent volumes were rated 18+.
舞台となるのは、夏恒例イベント！ザッショノ学園横断 レース！！ この大会で生徒たちがチャレンジするのはどれも過激な 競技ばかり。優勝チームには賞金も用意されている（？）ため 参加生徒の気合の入り具合はハンパじゃない。数々の難関を くぐりぬけ優勝の栄光を勝ち取るのは果たしてどのチームか？ 伝助のいるエイケン部は優勝することが出来るのか？
