Teisou Gyakuten Sekai no Doutei Henkyou Ryoushu Kishi

Faust was reincarnated from modern Japan into an alternate world where gender roles are the exact opposite of our world. He became a rare male knight in a world where women rule the land and men are in the submissive role. He achieves many military victories and is proclaimed a hero, but because of his sense of value from his previous life, he is constantly being tempted by the seductive, almost invisible, clothing of the queen, and non-stop sexual harassment from the big-breasted duke.......

(Source: Comic Gardo, translated)