Gyakuten Isekai de Yomeki Okure S-Rank Onna Boukensha-tachi ni Semarareteimasu

Ryou is a dull-looking office worker working for the Adventurers' Guild in Cassandra City. When he rescued a mysterious fairy trapped in a vial, he discovered he was transferred to a parallel world! In this world where men are scarce, and the values of beauty and ugliness are reversed, Ryou finds himself in a situation where he is irresistible just because he exists as a man!