@forevermel can't really understand your comment but what I mean to mine is that since Dooshik and Jooha's story is done, the Pearl Boy, and this story is not about them anymore but since it's the same universe there might be a chance we see them in here. But what I mean that they're background characters is that their role is not that big as it used to be in Pearl boy as it's their own story and they are the main characters. And to answer your question, yes, Jooha is now a background character as it is now about Seung-hyun and Yuta. Hope it answer your question and help you understand it.
I overreacting always in my comment because I type my honest opinion and what my mind say and also 
so no hate, I'm just a 14years old girl who reads BL and Wattpad secretly.
so no hate, I'm just a 14years old girl who reads BL and Wattpad secretly.