Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Romeo X Juliet
When Juliet and Romeo meet and fall in love in Romeo X Juliet. Because in this version they're actually likeable characters, and the knowledge of what's to come just kills you.
Episode 11, the "Romeo and Juliet are officially a couple" episode, consisting of mainly the two leaving the city for a day to just wander around all lovey-dovey. Like the last example: nothing obviously tragic, until you remember what you're watching.
Episode 15. Petruchio. Petruchio's death in Romeo's arms. *sob*
