Bishuu Gyakuten Sekai no Cleric: Bishuu to Teisou Kannen ga Gyakuten Shita Isekai de Souryo ni Narimashita. Inyoku no Noroi wo Toku Tame ni Harem Party de "Gishiki" Shimasu

After carefully considering his options numerous times, Makoto, a 30-year-old virgin, decides to go to a high-class adult shop so that he can climb "the stairway to adulthood". But there, he loses his footing on the stairs leading to the shop, slips, and ends up getting transmigrated into another world! In this world, the concepts of "virtue" and "ugliness" are the exact opposite from how they are on Earth, plus there's an extreme lack of men! At an adventurer's guild in the town he finds himself in, he's recommended the job of "cleric", which involves quelling "the curse of carnal desire" (horniness) from the female adventurers by performing a "ritual" (having sex with them)! Thus begins his never-ending, 24-hours a day test of endurance as he works to remove the "curse" from big-boobed elves, tomboy female knights, and lolis who have enormous breasts and talk like old men! Through his "ritual of love", will he be able to heal the emotionally-injured beauties who've been belittled and called "average-looking" by society?! Source: Shueisha