Talking to my friend she said she used to love a manga where the guy was really pessimistic and had low self steem, and had greyish/white hair. The girl had green eyes (I think?) and was in love with him, although the boy didn't notice her until he had to do a school project with her (I'm not sure about this one either). When the boy is saying pessimistic things and that no one loves him, the girl says "I do", kisses him and runs.
Thankss.