If you have read placebo crush then it's just that, a repost of that one. Basically season 2 is placebo crush. Just check if you have read it and if you did, then no need to read this season.
IF you haven't read it, then you don't need to read the 1st season. This is other pairing, so the only important thing you need to know is that:
1. Red hair guy is the younger brother of Woojin or something (black haired, tall guy, you won't see him until the middle of the season).
2. Blond guy is the boyfriend of woojin (red guy's older brother).
3. Red guy has a crush on his brother's boyfriend (blond guy).
5. Brown haired guy is the friend of blond guy.
6. Brown, blond and black haired guys are finishing college (or they are done with it), whereas red haired guy just ended high school.
7. It seems red haired guy is staying with his brother and blond guy while in college, or something. Either the author didn't clarify that, or I didn't pay much attention.
Someone Help whats Going on I don’t get Shit First of all I though we are done we Even have a Spin off and Shit and now a Season 2? And what happend who, how and what I don’t wanna Read Season 1 again but whats Going on