Genshiken: Ranto Hairu's Ambitions ~Return of the Otaku~ (げんしけん 拝入蘭人の野望〜Return of the OTAKU〜) is a Japanese novel written by Kazutoshi Iida and illustrations done by Shimoku Kio. It was published by Kodansha under the KC Novels imprint on January 21, 2008, with Del Rey Books licensing the English release.
The deafening whack-whack-whack of a helicopter above campus is the first indication that the balmy tranquillity of the Genshiken Club is about to be disturbed. The chopper brings handsome Ranto Hairu: transfer student, scion of a powerful Japanese conglomerate, and newly named chairman of the on-campus club organization committee.
Hairu has strong ideas about the kind of clubs that deserve to survive (earnest, industrious) and the kind that don’t (arty, frivolous), and he’s a big fan of brute force. For Madarame, Kousaka, Ohno, and the others, the idea of losing their cherished club is the ultimate nightmare—but it’s only the first of many.
Fortunately, the Genshiken boys and girls have a few tricks of their own, including a certain swordfighter summoned from ancient times who could prove very handy.
The book introduces Ranto Hairu, the rich grandson of one of Japan's most influential businessmen, as he takes over the student club organization with the intention of getting rid of any elements he views as unsavory. Meanwhile, a supernatural force is slowly abducting members of Genshiken without a trace.
Chronologically the book falls just after certain events in the second volume, although few of the book's events follow the story elements already established in the series. Changes such as Kuchiki remaining with the Genshiken after his initial attempts to join, the established president of the student club organization drops out due to pregnancy, as well as Ohno and Tanaka's relationship being more established than it was during this point in time. The light novel also introduces several characters that are only present in the novel itself and do not appear in the anime or manga. Also of note is that there are several elements present in the book (such as the supernatural) that are not present in the anime or manga.