Is Sayonara Zetsubou Sensei Special hentai?
No
Rated R (17+ (violence & profanity)) on MyAnimeList and not tagged as Hentai.

Special · 2012 · 1 episodes · R - 17+ (violence & profanity)
Comedy, Gag Humor, Mystery, Parody, Shounen
A new special episode that was distributed to those who purchase all three Blu-ray box sets of Sayonara Zetsubou Sensei series on January 31, 2012.
View on MyAnimeListShare
Check another title