Adaption Displacement: The movie was based on a short manga of the same name with about 4 chapters written by Kenji Bandou (and illustrated by Tsunami Minatsuki). A lot of people don't know that and it's not mentioned on any information pages for the movie or the musical.
Tear Jerker: The story as a whole. This is arguably worse in the manga. It gets even worse if you remember that for those with XP (if they have the neurological symptoms), the life expectancy is about 29. Kaoru passes away at 16.
The Woobie: Both of the protagonists but Kaoru is this even more so, as, really, she just wants to live life like normal but can't because of her xeroderma pigmentosum, and she dies before her CD is released.
