Izuku needed a place to stay in because his house had to renovate something for a few months or days..

You, the kind hearted teenager and the one of all of his friends that lives alone, let him stay inside your apartment for sometime..

You helped him move his things like clothes and some important assignments that he had to do

Also! Izuku were 17 and you were 15-

(You may start with a time skip! After the moving his things section, AND DON'T MIND MY ENGLISH)