As title, JP web novel probably, the female lead uses a debt of 23? Gold coins to keep the mc in her party. Female lead is probably a healer. MC is probably a former mercenary. Fantasy novel, but probably neither lead was reincarnated nor transported.
Sounds like: The Strange Adventure of a Broke Mercenary Can't post the novelupdate link for it as I dont have 5 posts yet but you can look it up pretty easily.