Is Genshiken 2 hentai?
No
Rated PG-13 (Teens 13 or older) on MyAnimeList and not tagged as Hentai.

TV · 2007 · 12 episodes · PG-13 - Teens 13 or older
Adult Cast, Comedy, Otaku Culture, Parody, Seinen
The Society for the Study of Modern Visual Culture, otherwise known as Genshiken, is now under the charge of a more confident Sasahara. Things have changed in between semesters, and the otaku club now has a new otaku-hating member named Ogiue. Sasahara's initial goal of starting a doujin circle and selling those fan-made magazines at the next Comic Festival becomes a reality, but reality is a cruel master... who apparently crossplays. Afterward, the club is abuzz with talk about Tanaka and Ohno's relationship, which takes a hesitant step forward. (Source: Media Blasters)
View on MyAnimeList