Story
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.
Synopsis via AniList (English).
Finished
Sayonara Zetsubou Sensei: Nyankin no Kirisuto
Comedy
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.
Synopsis via AniList (English).