Kanji Sasahara is one of the main characters, and the first to be introduced in Genshiken. He is a freshman at Shiiou University, with no other particular interest other than anime and manga. Once he finds a pamphlet for Genshiken, he immediately joins the group. Over his four years at Shiiou University, Kanji comes to accept himself for who he is and loses the inhibitions and guilt he once felt and associated with otaku culture, becoming an enthusiastic club member, and for a time, a capable club president.
In Genshiken Nidaime, Kanji has since graduated and become a professional manga editor. He is in a relationship with the current Genshiken club president, Chika Ogiue.
Kanji is rather plain in appearance, dressing in casual clothes. He has a relaxed and friendly smile on his face for the most part.
At the beginning of the series, Kanji is a shy, confidence-lacking freshman who on club day at university, decides to join a club he would actually enjoy. Kanji is just coming to terms with his otaku nature and much of the beginning of the series focuses on introducing him to the otaku lifestyle. He is the most balanced member of Genshiken, with no real focus on any particular aspect.
He is generally calm and level headed. However, he can be openly frustrated with other people when they show lack of motivation to complete a task, such as with Mitsunori Kugayama when he was days behind in creating artwork for the club's doujinshi. In the anime, there is a particular episode where Manabu Kuchiki's antics made him uncharacteristically burst out in anger.
As of Genshiken Nidaime, Kanji is a professional editor for a manga company and assists newer Genshiken members when he has time. He is currently in a steady relationship with Ogiue, who has since become a much more calm and relatable person, and also assists in editing her manga. He still keeps in touch with the former Genshiken members and goes out for drinks with them.