A wild ass speculation, but what if suo is part of a yakuza family?… ╮( ̄へ ̄)╭
ngl i dont think so. that would be too predictable since suos been traitor theorized since the beginning of the manga and his feelings and dialogue r genuine. he even apologizes to nirei and him laughing in front of him imo was just a front/facade to pretend he cares less than he actually does to get nirei off his back, even if just a little bit (impossible, nirei also knows its bull). i do think he might be affiliated with some gangster or bad faith organization which is forcing him to leave to some obligation but idk. i just know suo isnt going to be a traitor willingly, but i could see him being a traitor by force. but to me, by him leaving suddenly, i think hes trying to avoid the possibility of betraying them further in the future if thats even a risk.
Big papa is back! ⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄