I think it is a j movie but it could be korean, i'm not sure. It's about a guy who tried to kill himself but a girl stopped him. Then the girl kill herself and the guy i think travels in time to find out why she did it. Thanks 

I think it may be this drama Somehow 18

 DAeDaLuS426:

I think it may be this drama Somehow 18

That's the one. Thx!