It's a good manga your right but Reí was still living with his "parents" when he died. (Y'know those pieces of cr** that just beat their child to a pulp.) Thinking that Rei is a minor to me just is a good assumption for the fact that it seems like how old he is and for that he literally is the size of all the other species in his class.
You're emo 🖤 (hidden text)
Spoiler!
Why are you looking here? Are you looking here out of interest in me or the comment