@Mov its rlly weird to respond like 3 months later, but in this chapter it says "jang youngguk,who is a middle school student but has a middle aged mind." he is a middle aged man in a child's body, regardless if you think differently lol. He does not behave like a child would, because he is no longer a child. Even if his outer appearance is a child technically he does count as a middle aged man LOL
Im going to ruin my life