About the engagement: Yoshino's grandfather, Renji, literally coerced her into a fake dating situationship: he made up a story he sold to journalists, and from Kirishima's side, it was "them living together couldb be like marriage IF they vibed" (and we get later on what vibing with Kirishima means).
But the whole rumored situationship at the start is "they are dating and /it could/ lead to marriage".
The summary and the english title still feel so misleading compared to the first chapters' content in which they are only rumored as having an intimate relationship. From a more manipulative pov, I guess Renji left some room because it could be easier to deal with a break up than calling off marriage plans (in case his own scheme went wrong, needs to be discarded, or Yoshino and Kirishima wouldn't make it work). Engagement only works in the "involvement" and "contract" sense at first, not the promise to get married.
About Kirishima: "handsome guy with a promiscuous lifestyle and acts the way he wants", he is basically cut from the same cloth as Renji and Shouma, and it's like telling Yoshino, "Don't overthink this, be yourself, you know this type of man."
Dohu's thoughts always break my heart because they show how much hearing his parents' conversation when he was young, the bullying and his relationship with his ex shaped him. Already preparing for the worst outcomes is like a bad habit he can't shake, but expecting the worst looks like a way to protect himself unconsciously. And it's so cute to see his expressions when he's around people he's emotionally attached to: his ears turning red because of Juheon, how his eyes slightly widen when his older sister says his full name, etc.
Unrelated but I am a bit worried about the bully finding out about Dohu's BL work and thinking he was into him since Dohu was into trash tops. And still, related to writing, I hope Dohu will take an interest in directing... only because I want to see a situation: the bully auditioning for the movie without knowing Dohu is directing it.
Idk something about seeing him having to behave because Dohu would hold some power... It would be so satisfying.