It's about a girl who wakes up with amnesia in a random guys place, the guy tells her that her parents had died in a car crash. The girl is taken care of by this man knowing that he is a professor at a college, he is really nice to her and i remember a scene of him cutting her hair, he slips an amnesia potion thing in her coffee every day without her knowledge so she doesn't regain her memories. One day she realises that he forgot something at the house so she went to the college where he is working (I should add that the guy is a professor) to hand it to him. These two girls came up to her who seemed to have recognised her but she had no memory of them, while she entered the college her memories started to return to her. What had really happened is that her professor failed her test so she couldn't complete the course and couldn't leave him cause he was in love with her, he said to her that all she had to do to pass the course was meet her after school to try out a new potion he created which was a love potion (i think) that went badly and made her lose her memory.

Second story of Atashi wa Sore o Gaman Dekinai.

~4400 manga completed
~1700 ongoing...

Yes this is it, thank you very much.