I can't say for the manga since I don't have all the raws yet but when I skimmed the novel it seemed (to me, anyway) that Fizz views Koo in only a motherly way!romance manga
no shoujo ai tag
no other love interests introduced yet
the only male character close with the mc is the one that calls her mother
YOU BETTER STOP.
unless a kind soul would like to tell me that she gets an actual love interest that isn't her adopted son?