This is a cuck game, bro. So the answers no. You can't be big, strong, pro. You have a tiny dick. And don't cum much. Even random enemies on the floor are more butch. Your dick like 3 inch long, goblin has 2 foot dong, if you come into this to be a man then you're doing it wrong.
But seriously, no, the game has always, from the very first fight, been clearly aimed for cuckoldry above any other aspect. Shit like being able to train your sex skills and come on to other chicks were added later, likely because of how blatantly unbalanced the content was and people coming into a game with NTR in the game expecting balanced content. The MC has always had by far the smallest and least virile penis in his world, only being outclassed in smallness by 1 guy in 1 event who shoots a literal mountain of cum to compensate. Every random man from event squares, every enemy and yasuo all make him look like what he is, lil' dicky, dicklet extraordinaire.
Even when coming on to other chicks, he can't do that when kohaku's around, unless she doesn't notice in 1 single event. Otherwise she will inexplicably hit you harder than every enemy in the game. Somehow. Even if she's already devoted her entire being to another mans cock and is only following you because he said so.
You also can't leave an 'army of pregnant women in your wake' like that guy says. Not sure what he's talking about. There are very few other girls you can fuck and I don't think any get pregnant and I'm unaware of the dev saying that'll ever be a thing, pregnancy for random npcs.