The story revolves around a brother who is usually disliked, starting with his sister and her friends suddenly showing their panties as a punishment for losing a game, escalating to revealing their privates, becoming submissive, and eventually leading to sex. Initially, the sisters genuinely resist, but they gradually become curious about erotic things, unable to hide their true feelings, and end up being brought to orgasm by the brother's penis they once despised, resulting in a reversal of roles. The brother, who was just a tool for punishment, ultimately reigns as the best brother who provides pleasure, creating a dramatic turnaround. Performer Ichii Yuuka is cute and sexy, delivering an outstanding performance as a favorite. Although the content is somewhat cliché, the innocent vibe of the sisters is well-portrayed, making it promising for a series. Details like setting up a fixed vibrator and facial cum shots add to the enjoyment. The cast includes Uesaka Mei, Ichii Yuuka, Mochizuki Tsubomi, Izumi Rion, and Otowa Misuzu, with a safe borderline JK feel that allows for comfortable viewing. While the escalation of play is unclear in parts, the overall excitement makes it highly watchable. After watching it myself, I was drawn in by the psychological depiction of hidden desires under the guise of punishment. I eagerly await a sequel.