Ah, finally I watched this film. It's so late huh?
Well.. The story is simple. A girl named Kaoru (YUI) who is suffering from a decease called Xeroderma Pigmentosum (XP) which is also might be described as allergy from UV Rays. So she is not allowed to be exposed to sunlight. This girl has a crush on a high school student who loves surfing and one night they saw each other and Kaoru out of nowhere knocked the guy down and started talking about her feelings towards the guy and that’s where they started going out at night.
Yeaah when Kaoru died and when the song : "Good-Bye Days" started, I was crying and can't stop crying >,<