@kungfufool45King of harem stories, Redsliver, has some good options for you:
Blizzard - Guys a bit older, 31, but he goes from a coasting unambitious type to getting his life together and growing up. Sometimes you need to be loved and respected first to become loveable and respectable.
Magic is Gross 2 - MiG 1 just introduces the main three characters and the magic mechanics. It has a bit more options for that squicky turn off factor: gender switching and 3 is basically abandoned. It's supposed to be 80s grossout teen comedy meets Buffy-ish there are monsters in my high school. 5 girls summon a demon to make wishes, all 5 wishes are granted, to all 5 girls, one of which wished for love between herself and David, while one unwittingly wished to get pregnant.
Monkey Wrench - Guy is semi-abducted by aliens with nine other high school classmates, all girls. But there are others, and somewhere out there, his sister needs his help.
Space Nut - a serial pregnancy story, an alien lifeform crashlands in a small town and is using/feeding on Adam while binding and impregnating girls with him. Weird fun. I like it. One of my best written scenes in this one.
Blue Ribbon - takes place over a single day, so there's not a huge amount of coming-of-age, plus it's set inside a perverted game of random people have power over others, Leo is one of such people.
Hot Tub Love Machine - a kid and his five best girlfriends use a hot tub full of love potion. Turns out Lucas is being groomed for power by his dangerous Uncle and crazy Mom.
Shelter In Place on Haunted Hill - Set in the early days of the pandemic, a bunch of college girls take advantage of a bit of a simp until they find themselves forcibly quarantined, and the only way to stay Queen of the Hill is to control him, so he's forced to nut up and become King.