Eiken

• Name — Eiken • Ja Kanji — エイケン • Genre — Sex comedy

• Type — manga • Author — Seiji Matsuyama • Publisher — Akita Shoten • Imprint — Shōnen Champion Comics • Magazine — Weekly Shōnen Champion • First — April 26, 2001 • Last — August 5, 2004 • Volumes — 18

• Type — ova • Director — * Kiyotaka Ōhata (1) • Alan Smithee (2) • Producer — * Atsushi Moriyama • Nobuhiro Ōsawa • Yūji Matsukura • Writer — Tomoyasu Ōkubo • Music — Shō Goshima (Soft House Right Brain) • Studio — J.C.Staff • First — June 25, 2003 • Last — June 23, 2004 • Runtime — 30 minutes • Episodes — 2

• Portal — yes Eiken is a Japanese manga series written and illustrated by Seiji Matsuyama. It was serialized in Akita Shoten's manga magazine Weekly Shōnen Champion from April 2001 to August 2004, with its chapters collected in 18 tankōbon volumes. The story depicts the life of schoolboy Densuke Mifune after he is forced into the mysterious Eiken Club. It was adapted into a two-episode original video animation (OVA) produced by J.C.Staff. Both the manga and the OVA were licensed for English release in North America by Media Blasters.

Densuke has just enrolled at the exclusive Zashono Academy. He is very eager to participate in extracurricular activities, but never expected to join the mysterious Eiken Club. Strangely enough, every other member is a busty co-ed, and many of the club's activities involve bikinis. But Densuke is not interested in anyone except for the shy and beautiful Chiharu Shinonome.

• Chiharu Shinonome: • The red-headed Chiharu is considered one of the most attractive girls at Zashono Academy. She is shy around boys, because she came from an all-girls school. • Densuke Mifune: • A plain boy no one seems to notice, Densuke was forced into the Eiken Club after an accidental run-in with Chiharu, whom he develops a crush on. He eventually accepts his place in the club, despite being tormented by Kirika and the other mishaps that befall him, i.e. being beaten, violently crushed (Kirika, Yuriko) or electrocuted (Kyoko) by other members. Densuke is frequently forced to cross-dress by Kirika, a hobby of hers. • Kirika Misono: • Not much is known about Kirika, the purple-haired amazon that runs the Eiken Club. She likes putting Densuke in awkward situations for her amusement. • Komoe Harumachi: • The pink-haired Komoe is the youngest member of the Eiken Club at 11 years old, who dialogues with macromastia. Komoe is very clumsy, but always striving to do her best. Her clumsy mistakes often leave her exposed, and she has a habit of accidentally hurting and squashing Densuke when falling on him. • Gurēsu Rin: • Grace is a blonde-haired British girl who was born and grew up in China. She comes from a fortune-tellers' family and her father is a successful world-class enterpriser, also she is also very good at acrobatics. She seems to have a bit of feeling for Densuke as in the original manga, her words with Densuke in the speech bubbles are often ended with love-hearts. In the English version, her name was romanized as Lynn Grace. • Kyōko Morooka: • Kyoko is the small blue-haired girl who runs the science division of the Eiken Club, and would seem to be the second-in-command of the club. Despite her age, she looks a lot younger than she really is. She often hurts Densuke with her various inventions (rockets, electrocuters). In the English version, her name was romanized as Kyouko Morooka. • Yuriko Shinonome: • Chiharu's energetic sister, she looks like a short-haired cheekier version of Chiharu. Despite being fully aware of Densuke and Chiharu's feelings for each other, Yuriko likes trying to get between them. • Advisory Teacher: • Sensei is never named, though she is a teacher from Zashono Academy, she often laments the fact she always seems to go unnoticed by her students and peers, not to mention the fact that they never seem to remember her name. She has bright green hair. In the English version, she was simply called the Teacher. • Kuma-chan • Teddy is a very shy young girl, who wears a giant bear suit most of the time. She has an older sister, who also wears a similar suit. • Miharu Shinonome • Jun Shikano • Chiharu's cousin, who also has a crush on Densuke. Her timetable always seems to be occupied by many part-time jobs. Densuke eventually finds out that she is secretly funding detectives who promised to find her long-lost father who left almost without a word after the divorce (due to the bankruptcy of his factory). • Chō Ginten • She is head of Zashono Academy's Committee of Student Accountants. She had mysteriously returned to the academy over a two year span with an immediate action of carrying out her own budget plan to forcefully cancel all the activities of all the clubs in the academy, despite all the dirty tricks she has in mind. • Hikaru Daizenji • The ex-head of the Supernatural Club in Zashono Academy, a slim and weedy girl whose body is dotted with bandages from the countless bruises and wounds caused by falling due to fainting resulted by her anemia. • Keiko Shinonome • The mother of the Shinonome family. • Mikito Shinonome • The younger brother of Chiharu. He first appears pretending to be Chiharu in order to test Densuke. He is practically Chiharu's twin, and it is hinted that he is interested in Densuke, whether that is true or not, is not known. • Shima Kurosawa: • He is the champion of the previous academy tournament who has returned from America to win the heart of Chiharu Shinonome. He is aware of Densuke's feelings for her, and feels that competition is the only way to resolve the romantic triangle.

Written and illustrated by Seiji Matsuyama, Eiken was serialized in Akita Shoten's manga magazine Weekly Shōnen Champion from April 26, 2001, to August 5, 2004. Akita Shoten collected its chapters in 18 tankōbon volumes, released from October 5, 2001, to November 20, 2004. In North America, the manga was licensed by Media Blasters. They released 12 volumes from July 1, 2005, to September 17, 2008. A manga remake using artificial intelligence art began serialization on Beaglee's Manga Ōkuni online platform on April 25, 2024.

A two-episode original video animation (OVA) adaptation produced by J.C.Staff was released on DVD from June 25, 2003, to June 23, 2004. The opening theme and ending theme, "Feel Like Our Days" and "Jewel's Memory", respectively, were both performed by Toko. In North America, the OVA was licensed by Media Blasters. It was released on DVD on December 14, 2004, and on Blu-ray on July 31, 2020. It was added to Crunchyroll's catalog in September 2020.