for them it's a HAPPY ending because they all graduated and still they are friends. for me it's a HALF HAPpY ending because the story is not enough!
Yes, it does.
Yes, or it appears they did. Which made the ending very sad, considering he killed her.
The end is kind of sad, at the end, and it is kind of sad when the are going in the incinerator.
A tragedy is any play with a sad ending while a comedy is a play with a happy ending. Romeo and Juliet is considered a tragedy because both of the youthful, innocent lovers end up dying.