Responses
Well, in the previous chapter he mentions something about a favorite movie from when he was little, and the Uke thinks "well so he is aware that he is an adult". In this case, I think it's just some kind of trauma, but no age regression involved.
the ml’s trauma caused his personality to split when he was a child, but both the personalities have aged as he grew up. he’s not age regressing, his other personality is just his vulnerable/childlike side
well now this made me wonder…how old is this new persona of our ML supposed to be?cuz bro having child like expressions does NOT help the case