Guys I'm Having a hard Time finding a anime that is very interesting . .
Something in category that is (Romance, action, sci. fi, and a lot of school life.)
but more likely It started in tragedy . .
Starting in something that is like .
at the first place that something happened in the Boy/Girl
That Includes in the tragedy. and started on a new school with an amnesia.
And as time/day/week/year passes by he/she started to regain his/her Memory . . . .
maybe you could provide some more details because right now they are very vague. however for some reason the first anime that came into my mind was Angel Beats! ...
If you remember a little girl eating taiyaki who has a backpack with wings on it, then the anime is most likely Kanon. If you remember a band playing (Girls Dead Monster) and the world of the afterlife, then it is most likely Angel Beats.
Like ewaldhew said, more information would be helpful in helping you figure out which anime it is.