Responses
Oooooo following
http://www.mangago.me/read-manga/the_moon_is_beautiful_tonight_but_first_die/
pretty sure it's this
Yup that's the one , Thanks
A manga about this guy who is in love with his childhood friend then he catches a virus or something that make you want to kill the person you love so he tries to kill her on the roof top of their old schooll buliding but it collapses they survive and the girl pretends she lost her memory of it