Can't have a bl without some grooming
Well I don't think the age gap is that big (perhaps it's just me...)
Miyai meet him when he's 13-14 (and now Miyai is 17-18)
His tutor have an elite brand, maybe he's skipping 1 grade to Uni (Japan allow so) he can be 18-19 at that time
But according to this kind of lovey dovey author, sexually behavior toward a minor won't happend
In chap 12, I think the tutor turned Miyai down, Miyai is smart, he can learn about stuff by himself it's not really that things happend between the two
Well see yall in Christmas