I can't really find a good suggestion so I'll rate it like this:
Writing Quality 5/5 - Barely any mistakes, great grammar, regarding monologues, it'll be in Character Designs
Writing Stability 3/5 - Nothing to say.
Story Development 4/5 - Probs too early to add this in, the series is still in infancy stage, but overall, loving the slice of life related stuff, really refreshing. The deduction tho, I can't really explain, so I'll just say 'instincts'.
Character Design 5/5 - The characters so far looked really good, the relationships aren't black or white(so far), and not 1 dimensional, which is really hard to do.
And really gotta appreciate how small details such as, being handsome/beautiful, or him being really good at things and other irrelevant stuff were not emphasized that much. Like for an example would be him/her being handsome/beautiful making the guy/girl blush for no (bleeeeeeeeep) reason, which I'm really tired of. Especially when you added that depressed guy to his circle, which thank god you didn't add unnecessary drama because l he was self-conscious about himself.
A con I found missing was a small detail, which should be noticed by his parents, such as 'maturity' when he came back, 'cuz he spent 10 years in another world, in which many dangers lurk. Nonetheless, it's negligible.(In my opinion)
World Background 4/5 - Hm... since I suck at describing stuff like these, I'll just say it's too early. But the foreshadowing about some stuff tho, fairly well done.
The reason for the deduction would be... Instincts. (Jk, it's the demon king stuff cliche.)
