FL exits relo coz husband cheating, becomes homeless. ML highschooler dangles cash at homeless for fun, but she berates him. When he finds her homeless, he bullies her - eventually gives her a room at his place. She accidentally damages a painting, he makes her play a 'game' to pay him back. Game involves insulting a girl for him, confronting her ex etc. cruelty. Eventually grandma arrives and puts end to it. They both are developing feels tho and dont want to part yet. poor little rich kid w no friends and everyone only wants to associate w him coz of money, except her. She works for his gma at ryokan, meets his big bro who she knew in school. More unfortunate events, turns out girl who liked big bro set up FLs ex to cheat as revenge for hurting big bro (who liked her, but FL couldnt be w him due to abusive father, and then later got married to someone else). FL and ML end up together, waiting until after he turns 18 of course lol. A bit too grooming - in the drama they age him up.
Promise Cinderella