Pretty sure it's been NSFW since the beginning of the final season.
A lot of manhwas actually unfold like this. The main story is R15+ but the side stories become 19+
I may be wrong but I think the novel had these side stories and the manhwa follows the novel. idk it's been a while since I read it but, the creators do talk about the side stories on their social media and I believe some create a new page for the side stories especially if they're 19+ (on official websites).
There's also R15+ side stories - basically these side stories but it doesn't show the smut part js the kissing and stuff so if you don't wanna see the smut you can go on the official web ridi and read that :D
shiiii i talk a lot mb gng
brother I thought this was R15+ and didn’t have smut in the side stories? Like I don’t really mind it ig (?) but I thought the author had confirmed that is NOT NSFW. So tw for that.