「突然課外授業!」とナンパされた禁断の関係の●校生ペア4組が、賞金を賭けて保健体育ビンゴに挑戦!生徒会長×書記、幼なじみ、バレー部先輩後輩、友達の彼女…。様々な関係性の4組ががビンゴ1マスごとに崩壊する背徳の保健体育授業!「どうしよう…」「見ないで…」「やっぱりダメだよ…」とためらいながらも、なし崩し的にSEXまで発展!明日からの学校生活で顔を合わせるたび、あの密室の記憶がフラッシュバックして股間が疼く禁断のトラウマ課外授業!
“Suddenly extracurricular class!” Four pairs of school students in a forbidden relationship challenge themselves to health and physical education bingo for the prize money! Student council president x secretary, childhood friend, senior and junior in the volleyball club, friend’s girlfriend… An immoral health and physical education class where four groups with various relationships collapse every bingo square! “What should I do…” “Don’t look…” “It’s not good after all…” While hesitating, it gradually progressed to sex! Starting tomorrow, every time we meet in school, the memory of that closed room will flash back and my crotch will tingle! A forbidden traumatic extracurricular lesson!