Yuri lovingly kisses her worried husband goodbye and heads to her long-awaited class reunion. There, she unexpectedly reunites with her ex-boyfriend Tatsuhiko, the carefree playboy from their school days. As the night unfolds with drinks and nostalgia, Tatsuhiko's bold advances test Yuri's loyalty—leading to a shocking turn in the bathroom where his feigned illness reveals a calculated trap for seduction.