【A popular work with over 94,000 copies sold in the FANZA doujin series, a luxurious collaboration with Riho Shishido!】 Okamoto, the protagonist, falls in love at first sight with the cool-type girl "Ryo Watanabe" he meets at his part-time job, but he can't get close to her. In the meantime, he ends up taking care of Watanabe-san, who rarely participates in drinking parties, and learns a certain secret about Watanabe-san. [It seems that she becomes super horny when her nipples are touched!?] After getting close to her due to an accident and spending a super horny night with Watanabe-san, who has become horny, knowing her secret and continuing to date safely, the two decide to go on a New Year's visit date. From that point on, Okamoto is stirred by his desire to monopolize Watanabe-san and takes her to a secluded place... The electronic-only original manga of the main story is also faithfully filmed! Collaboration with a popular doujin work! The original doujin works "Her Estrous Switch" and "Her Estrous Switch 2" are here!