Gyakuten Isekai de Ikiokure S-Rank Onna Boukensha-tachi ni Semarareteimasu

As a reward for saving a mysterious fairy, Ryou has been transferred to a parallel world where the values of beauty and ugliness are reversed!? In a world where the gender ratio is overwhelmingly more women than men, he is relentlessly pursued by beautiful women and girls. A tale of erotic harem life with exquisite adventurers.

(Source: Kadokawa, translated)