DKD-010 Despite being a shut-in and a gloomy girl, my sister has huge tits and is cute. She only sucks my dick. Tsukino Kasumi.

In her second year of high school, Kasumi suddenly became a recluse. For several years since then, she had been living a self-destructive life without stepping out of her home. While streaming online for tips, she was ridiculed by viewers as 'not great at conversation or flirting' and told that she should 'lick a penis at least once for the experience.' Her brother, Yuto, who secretly harbored special feelings for his sister, accepted her request, leading to Kasumi performing fellatio on him every night. One day, when Yuto said he wanted their relationship to go beyond siblings, Kasumi rejected him with 'because we're siblings.' Angered, Yuto started dating a female classmate as a way to spite his sister. Seeing this, Kasumi's emotions were greatly shaken. Even though he was her brother and not her lover, she had only wanted to see his penis... She felt intense jealousy for the first time. 'I can't forgive it, Yuto's penis is mine!' Is this lust or love? Tsundere sister complex girl Tsukino Kasumi passionately performs! ※Due to the nature of the work, some scenes may have rough visuals