it season 3 is going to happen, then it's going to be the Cheongang arc.

The main characters this season are: Yeon Si-eun, Ahn Suho, Park Humin, Go Hyuntak, Seo Juntae, Geum Seongje, Mr. Choi, Lee Juwon, Seol Giju, Kim Doyun, and Lee Jaeryeong. 

This season will focus on the Cheongang arc, instead of Union vs. Cheongang. It's going to be Eunjang vs. Cheongang — high schoolers vs. gangsters.

The theme of this season is that Yeon Si-eun and his friends are already seniors, except for Suho. Humin finds out why Baekjin became evil and how he died, and seeks revenge against Cheongang. There will be more gang activities and brutal fights. The season will end with graduation

I do hope that'll be the case. I'm still wanting for more of Suho and Si-Eun's scenes, and Si-Eun introducing his bff to his new friends. The ending in S2 was pretty much the ending in the webtoon but knowing Netflix, they could make a new installment to the series (which we are rooting for). 

I truly hope they make a 3rd season. Hopefully Netflix will lean more into the webtoon but idk, for sweet home Netflix added a different story and didn't follow the webtoon :(