Responses
Sounds similar to Hyperventilation, which was adapted from the anime with the same name.
https://www.mangago.zone/read-manga/hyperventilation/
Is it "love plan"?
https://www.mangago.zone/read-manga/love_plan/
It's called love plan.
In this the uke (black hairs) and seme (blonde) reunite in a reunion. Seme is kinda obsessive but seme pretends he doesn't know uke at first just to take little revenge it was reunion after 8 years as i remember and they both get drunk and they have a one night stand and seme says to date for one month. It's a short 10 chapters manhwa ig