College student Kanade visits his girlfriend Aimi's home for the first time. There he meets her younger sister, Kaede—a cute yet wild and carefree girl whose braless, sheer top constantly reveals glimpses of her ample breasts. Unaware of how she's flaunting her bigger, voluptuous body compared to her sister, she tempts Kanade with a mischievous, devilish charm. His arousal quickly grows uncontrollable. Sensing his excitement, Kaede presses her G-cup breasts against him seductively, whispering, "Bigger than my sister, right?... You're starting to like me, aren't you?" Overcome with desire, Kanade gives in, losing himself completely as he starts fucking her every day. A story of a worthless boyfriend consumed by lust and guilt.