Unrealistic and immersion suspension damaging that this boy can't even carry a cardboard box of school supplies. How short would you have to be to not do such a simple task, really? Even if he's only like 5 foot tall he looks normal in proportions and so must weigh in the 100 to 120 pound range. Unless, what, short for the little Japanese is, like, 4 foot tall?
But all these figures are academic (and not in the positive, rigorous sense). I'm less than inch under 6 foot tall and flagellate daily in penance over my bones not having elongated enough in my growing years. All those bad habits from not drinking enough milk, eating vegetables, sleeping well bring out a soul pain only banal pain can cleanse. I stand in lines and can't see the counters. I wear shoes all the time and others flip and flip around, looking down upon me. I walk around and see kids taller than me. Even my wife is taller, for Christ's sake. If I were to be 5 foot tall (let alone 4 foot tall) in high school, I would just take that cardboard box and snap my pencil thin neck with it.
Therefore, the existence of such a being as the male lead is unbelievable and patently ridiculous.