Incidents Happen in a Secret Room! Dokuro-chan!, It's Valentine's Day Kiss! Dokuro-chan!
Available on Prime Video
Sabato's mother informs everyone that Sabato has to return to the future, but Sakura tries to stop her from leaving, thus everyone ends up in a prison cell. Many attempts to escape go very wrong. Dokuro makes Sakura chocolate, shaped of himself, for Valentine's Day. However, she adds a special "binkan sausage" which makes Sakura really "special" and also gives him an allergic reaction.

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