I don't hate him like I did at his introduction (I've grown to enjoy him significantly more since then) but Yusuke's character is notably inconsistent and you can't deny it.
One moment he's the intelligent voice of reason, worldly and wise, with great insight on the human experience. The next he's an oblivious idiot who can't make sense of anything. One minute he's oversexed and thirsty as hell. The next he's asexual and totally ignorant to innuendo and attraction.
And these are not "layers" to the character or "human complications" or anything -- they're contradictions. They're the result of unfocused characterization, which is the writing's biggest drawback. (He's certainly not the only character who suffers from this but is the most noteworthy.)
These dissonant bits are usually in moments played for laughs so I could see how some might forgive them, but they come at the expense of the integrity of the character. The humor should come out of the unique and distinct consistencies of these characters, butting up against each other in scenes... but instead it feels like character is often broken for the sake of a cheap laugh or gag. Idk.
Idk. Idk. This game is astounding. I'm 75 hours in. It is quantifiably better than P4G in nearly every way. And yet the flaws stand out to me way more than they did when I played Golden.
Still trying to unpack that response.