Skill issue, was able to do it around 40 something from my memory, how you might ask, simple, DETERMINATION, AND IDIOCY (and an ungodly amount of supplies)
I farmed for way too long and reached level 174... having this much power wasnt the way to play... now its just a dating sim and I dont really have the choice to fail... I mean you can give up but thats different dialogue entirely... beating one of the characters with more than 100 levels gives unique dialogue though so thats pretty neat!