Whispered by her gloomy younger sister, "If this gets discovered, your life will be over," her rationality is shattered, leading to multiple internal ejaculations—a POV of an extreme, penile-itching woman. Sairina Hyakuna DSOD-002

The male protagonist, arriving at his girlfriend Mizuki's house, encounters Mizuki's younger sister, "Sarina." Although Sarina is a cold and aloof girl, she secretly uses lewd words and sexual traps to seduce him when Mizuki isn't looking! Once aroused, she will masturbate or perform oral sex on him until he ejaculates without his knowledge! Sarina's seduction escalates, even leading to sexual intercourse! Under her relentless temptation, his reason completely collapses… and he can no longer stop ejaculating inside her…