How did Kanade die?

I don't think it was ever revealed but


SPOILERS



I don't know if you finished the series yet, but it could have had to do with the heart transplant? It worked for a while but then gave out? I don't really know how heart transplants work

Kanade's death wasn't revealed, like much of the others, Including the rest of the GlDeMo Band members, Shiina, Noda, Ooyama, Matsushida, and TJ (Of course there are more though) Kanade was most likely there for a very long time OR Time flows much more slowly in the Afterlife, seeing as how she was able to design and implement powers into herself, seeing as how Yuri seemed to hate Kanade for a long time, and Yuri didn't die too long before Yuzuru, seeing the kinda of technology The Nakamura family's house had much modernized technology. (This was all show in Yuri's Flashback Episode, I forgot the Episode title and number though.) Also! About the Transplant, Kanade was most likely Dead before Yuzuru's heart got to Kanade so She died quite a while before he did (Taking into consideration about the Slow timeflow of the Afterlife)

I'm not to sure about this, but I think that Otonashi since he had amnesia just wondered around different afterlife a until he came to that one. He wasn't supposed to be in that afterlife at all because he sucsessfully saved everyone and donated his heart. Kanade probably got that heart transplant which let her live longer, but it wasn't enough to save her.

Well... Yuzuru didn't really have regrets in his life since he pretty much accomplished them... and he even says so in the show. My hunch is that when Kanade died and she had his donated heart, he got sent to that world as well. Although she was there before him, I really can't think of anything else that wasn't already proposed XD

I honestly don't know the real answer, but since they both wondered into that afterlife school, it might have been that it took Yuzuru longer to find the afterlife school, and by then Kanade was already there because of how much she wanted to thank her donor for extending her life, and Kanade died because she had something wrong with her heart and needed a donor to extend her life because even with a new heart it will only let the person live longer before they give out.