## In the *Angel Beats!* universe: ##

The anime didn't reveal what happened to the people who passed on. There is a chance that the [visual novel][1], with its first volume setting out to be released on May 29, 2015, might explore this topic a bit. Until then, we can only refer to side materials, such as the third drama CD [released with the sixth limited edition BD/DVD volume][2]. In the drama CD, everyone reincarnated as a human being with a similar look (except one guy), but not a similar personality (except a few). They all met in the Afterlife World for the second time after dying again, and they were able to recognize each other and remember their previous lives.

## In the Keyverse: ##

There are actually recurring themes and concepts that connect together *Angel Beats!* and the four pillars of Key productions — *Clannad* (spring), *Air* (summer), *One* (autumn) and *Kanon* (winter). (Note: *One* is published before the founding of Key, but is still part of the Keyverse.) In *Clannad*, there is the [Illusionary World][3]:

> This world is later revealed to have been created by Ushio, who died regretting having left her father alone. She therefore became the girl in this world with the hopes of meeting her father again and collecting enough light orbs to make a miracle possible. [...] In theory, the Illusionary World is the after-life; when a person dies they are still connected to the real world, yet they are free to create their own world. 

In *One*, there is the [Eternal World][4]:

> The Eternal World is a place similar to the afterlife where a person's "other self" awaits. Anyone can access it, though it is only accessible once one has lost his or her grounding in the real world. It may be necessary to form a pledge with someone in the real world as a guide to the Eternal World, but one's memories surrounding the pledge become vague. A grace period can be granted between when the pledge is made and when someone goes to the Eternal World. Once the process has started, nothing can prevent someone from going to the Eternal World, and returning to the real world is difficult.

Don't they sound like the [Afterlife World][5]? The quoted texts even explain the [time gap][6] and Otonashi's (and Kanade's) vague memories surrounding his (and her) past life. Furthermore,

> Someone about to leave to the Eternal World starts to be forgotten approximately one week before going, and the amount of time before someone forgets differs based on how much someone thinks about the person leaving. However, he or she is remembered the moment that person returns. If a strong emotional bond is established in the real world before leaving, a person in the Eternal World can be returned after approximately one year.

So Kanade left friendless could be caused either by her friends in the Afterlife World having passed on, or by her friends in the real world having forgotten her. I don't know if the one year period is a hard rule or not, but maybe that is the reason why Otonashi didn't pass on immediately following Kanade.

So, in the Keyverse, what happens when a person passes on from the afterlife? In *Air*, [it can be a little tricky to determine what exactly happens there][7]; in *One*, the protagonist returns to the real world; in *Clannad*, [Tomoya returns to a past point in time after collecting enough light orbs to grant his wish][8]. Kanade and Otonashi were able to meet again in the real world either because:

 1. like Tomoya, they had been helping people achieve happiness by completing goals, so the [light orbs][9] that appear in the [OP][10] and in [episode 13][11] granted their wishes and brought them back to a time before the train accident while preserving their memories (following *Clannad*'s story); or
 2. they had established a strong emotional bond in the real world before leaving, which ensured Otonashi's eventual return after one year (following *One*'s story).

In fact, judging by Otonashi's hair in the scene after the end credits, they were brought back to a time before Hatsune (Otonashi's younger sister) died. Interestingly, "Hatsune" literally means "first sound", like the first sound of heart beat of a person long thought to be dead.

  [1]: http://angelbeats.wikia.com/wiki/Angel_Beats!_%28visual_novel%29
  [2]: https://en.wikipedia.org/wiki/Angel_Beats!#Broadcast_and_distribution
  [3]: http://clannad.wikia.com/wiki/Illusionary_World
  [4]: https://en.wikipedia.org/wiki/One:_Kagayaku_Kisetsu_e#Story
  [5]: http://angelbeats.wikia.com/wiki/Afterlife
  [6]: http://anime.stackexchange.com/questions/206/how-is-it-possible-that-kanade-has-otonashis-heart
  [7]: http://anime.stackexchange.com/questions/6803/is-there-any-canonical-evidence-that-the-winged-being-curses-were-really-lifted
  [8]: http://anime.stackexchange.com/questions/195/what-happens-at-the-end-of-clannad-after-story
  [9]: http://clannad.wikia.com/wiki/Light_orbs
  [10]: https://i.sstatic.net/j5fet.jpg
  [11]: https://i.sstatic.net/KL9BL.jpg