Shokushu Nyurunyuru Inma Kyoushitsu ga Gensoukyou Iri

A mysterious classroom suddenly appears in Gensokyo, filled with tentacles that capture and violate the local residents. Alice Margatroid and Marisa Kirisame are the first to fall victim to the classroom's traps, quickly followed by Patchouli Knowledge. As the threat spreads, Sanae Kochiya and Aya Shameimaru are also caught and subjected to the tentacles. Ultimately, the incident escalates into a bizarre competition among the residents to see who can withstand the lustful attacks.