In the last episode, Kanade graduated and disappeared. After that, there's a scene where Otonashi meets Kanade outside in the afterlife world. Did they reincarnate and meet again, or have they met before when they were still alive?
Due to long answer on duplicate question on How is it possible that Kanade has Otonashi's heart? and this question is only part of it, I decide to answer this separately.
On that question this is what happen on Angel Beats epilog:
The Alternate World Timeline
- Yuzuru gets reincarnated/reborn in the same universe that contains the main world timeline, but on an alternate and better timeline.
- Kanade gets reincartated/reborn in the same universe that contains the main world timeline, but on an alternate and better timeline.
- Yuzuru finally meets up with Kanade and they live happily ever after.
However, this is only theory and speculative answer, but from the fact that on this epilog
Kanade is humming Iwasawa's song titled "My Song"
"My Song" is created on afterlife by Iwasawa herself. So it means that this really happen after they met on afterlife, because there's no way she know that song if she didn't met Iwasawa before.