Board Thread:Questions and Answers/@comment-206.53.54.152-20140302014636/@comment-203.177.46.157-20140304132133

Remember, Otonashi died with his heart's desire. He passed away and living up to a happy life (due to the fact he donated his body to people who may use it of value).

The Afterlife School is built for young soul's who were not contented in their life or you could say people who could not meet their dreams in life (so Otonashi isn't really fit or have no connection about that world). This is when Kanade comes up- Kanade wanted to "thank" the person who saved her (the one that donated a heart,Otonashi). But since Otonashi died long before- Kanade couldn't "thank" the person, that's why she ended up in the School (not having her life fulfilled). In Otonashi's part, since he is needed for Kanade's wish to be granted- he was revived at the school for that mission. And because of the span of time til he got back to life again, somewhere he had lost his memories causing amnesia.

Overall to sum it all, Otonashi was needed for Kanade's wish- the reason why he was summoned in that world. Even though he died first.

Any more queries?

-A Wikia Contributor. xD Call me Stratus too :P