毎日、朝練と放課後の練習で部活漬けだった妹。そんな部活に打ち込んでいたマジメな妹が引退。現役中は部活でストレス発散していた妹は、引退後部屋にこもりがちに。中を覗くとえげつないオナニーで何度もイキまくっていた！有り余る体力が行き場失い性欲に化けて暴走？そんな妹の姿をこっそり覗いたらバレてしまい、慌てて謝ったが様子がおかしい…実はオナニーだけでは、全然発散できない性欲をボクにぶつけてきた！体力と性欲が有り余った妹と汗だくで何度も追い込みイキ！運動が苦手で体力が人並み以下のボクのチ○ポを酷使…。もう勘弁してくれ！

My sister was immersed in club activities every day, with morning practice and after-school practice. This serious sister, who was so dedicated to her club, has now retired. While she was active, she relieved her stress through club activities, but after retirement, she tends to stay holed up in her room. When I peeked inside, I saw her masturbating intensely, climaxing over and over again! Was her overflowing energy, with nowhere to go, transforming into uncontrollable sexual desire? I secretly peeked at her, but she caught me and apologized in a panic, but something was off… In fact, she was taking out her sexual desire, which couldn't be satisfied by masturbation alone, on me! My sister, overflowing with energy and sexual desire, and I pushed each other to climax over and over again, drenched in sweat! She abused my dick, which is below average in stamina because I'm not good at sports… Please, no more!