Jonan Senki Teisou Kannen ga Gyakuten shita Uchuujin no Guntai de Ace Pilot no Ore dake ga Yuiitsu Otoko na Hanashi
女難戦記男女比1対10の女性上位の軍隊で、エースパイロットの俺だけが男の話
The Story of an Ace Pilot Who Is the Only Man in an Alien Army Where Chastity Has Been Reversed
WN is Complete with 300 chapters
It's a Mecha novel
Hope this title gets picked up for PDF/EPUB
https://www.novelupdates.com/series/the-story-of-an-ace-pilot-who-is-the-only-man-in-an-alien-army-where-chastity-has-been-reversed/