Called it, the classic switcheroo of romcoms
Go to the other girl, reject her, then go back to the actual main heroine, which is usually also the "first girl"
She's a good girl honestly, both are good actually
oh would you look at that, First girl wins again. Sometimes I wonder why I even bother with these harem types, maybe I was hoping for Botan to happen again but I guess expecting something like that was my own delusions at work. What a shame.
I swear very few manga seem unable to get away from the First Girl Wins trope. And many times, they're also the worst girl in the cast (I'm looking at you Nisekoi).