I was wondering, would Koga (Inuyasha wolf demon guy) fit in your rat tier boyfriend category?
No… isn’t Koga like Ryoga from Ranma? They’re ovarall good boys and their only sin is to be a bit dumb. My rat tier category refers to those idiot bastards than when you see them you immediately feel like kicking their asses but not because they’re bad people (at all), but because their cockiness and often questionable -and embarrassing- behaviours make them kinda gross… yet those same elements make them funny and their usual nonchalantness give them charm, so -to everyone’s disgrace- you still like them. Within their series they most likely are bullied by one or more of their own allies because of how annoying they are.
If you want a concrete example, the epitome of rat tier to me is Zapp Renfro from Kekkai Sensen. You don’t even need a body pillow of him because sleeping with a trash bag will probably have the same effect.