Ore wa Lolicon ja Nai!

Shouji Osamu is an elementary school teacher fresh out of college about to embark on his first day. At the school gate, he was suddenly hugged by Chise, a girl he doesn't recognize who seems to know him. He later finds out that Chise is a fifth-grade student in his class, and that she lives in the same apartment building as he does. During a late-night rendezvous, he learns that nothing about their encounter is coincidental. (Source: MangaDex)