A student unknowingly sleeps with a girl who turns out to be a yakuza woman. Shoko Akase, a serious, kind, and seemingly saintly female teacher, comes to apologize—but her weakness is exploited as she's blackmailed into becoming a sex slave. Despite desperately trying to endure, she is repeatedly forced into intense sexual acts, awakening the succubus hidden within her voluptuous body, causing her to react wildly and uncontrollably.