After walking up in the Afterlife, Otonoshi can barely remember his past, save for a silver-haired girl named Kanade...
Memories of an Angel is a Angel Beats! fanfiction that follows Otonoshi and Kanade as they reunite in the Afterlife after spending their previous lives together. It can be read on Fanfiction.Net here 
or Archive of Our Own here.
Memories of an Angel contains examples of:
- Adaptational Late Appearance: Otonashi doesn't meet Kanade in the Afterlife until Operation Bait instead of his first arrival.
- Berserk Button:
- Calling Kanade a freak is one for Otonashi, reminding him of her former bullies.
- Of course, any harm or threat to Kanade is a berserk button for him.
- Chekhov's Gunman: TK on occasion would vanish from the scene before reappearing. It turns out that he had moved on after hearing Girl De Mo's music, before dying again and coming back. This reveals that not only do the students are reborn as humans when they move on, but can even keep their memories.
- Childhood Friend Romance: Otonashi and Kanade had been friends since third grade, and have dated since high school.
- Dead Guy Junior: Sora Igarashi, Otonashi's friend from the train accident, named his son after the latter.
- Death by Adaptation: Hatsune, Otonashi's younger sister, died at age six while her brother was only seven.
- Dying Declaration of Love: Otonashi proposes to Kanade, which leads to them moving on to their next life.
- Freudian Excuse: The day that Yuri arrived in the Afterlife, she saw her dead siblings, only for them to move one since they saw her. Kanade's vague answer to what happen only led to Yuri blaming her for her sibling's disappearance, leading to the latter to start to attack the former.
- Happily Adopted: Otonashi wanted himself and Kanade to do this for Naoi after learning about the latter's home life. Unfortuently, Otonashi death and Kanade's grief made that impossible.
- Living Emotional Crutch: Yuzuru and Kanade were this for each other in their previous lives. When Yuzuru died, she fell into a recluse and became devoted to her programming.
- Mistaken for Cheating: Since he didn't know that Otonashi had arrived, Naoi thought that Kanade was betraying the former by entering the boy's dorm, thinking she was meeting a different boy rather than Otonashi himself.
- Not What It Looks Like: Kanade tried to restore Otonashi's memories by giving him shock therapy with her Electric Saber. Yuri, of course, thinks Kanade was attacking him when she finds his charred body. Thankfully, she remembered what Otonashi said about Kanade's social skills and asks her to clarify when the latter just says she was helping Otonashi.
- Older Than They Look: Otonashi died in his 20, while Kanade died at 32, but both appear to be 16. And that's not accounting the decades Kanade and the Battlefront members spend in the Afterlife.
- One Degree of Separation: Among the passengers Otonashi helped was Oyama's mother.
- Out of Character Is Serious Business: Yuri takes notice when Kanade seemed distressed after hearing that Node beheaded Otonashi.
- Poor Communication Kills: Kanade often gives vague answers to others, which doesn't endear her to Yuri.
- Reasonable Authority Figure: While initially furious at Otonashi's "betrayal," Yuri does admit to herself and the battlefront that Kanade was trying to help them rather than obliterate them as she first thought.
- Shipper on Deck:
- Even though Angel had been their enemy, Hinata doesn't hesitate to cover Otonashi from the other Battlefront members while the two reunite.
- Played for Laughs when Kanade wonders if Yuri would become their daughter-in-law if she and Naoi started dating.
- Ship Tease: Between Otonashi and Kanade, as Hinata and Yui and Naoi and Yuri.
- The Unfavorite:
- Otonashi was often compared to his younger sister by his parents from everything from his grades to how many friends he had. Eventually, he moved out at 17 and went to live with the Tachibana family, who had a room ready for him since he was 12.
- As in canon, Naoi compared to his dead brother, which leads to him and Otonashi bonding during the train incident.
- You Didn't Ask: Kanade's reason why she didn't tell Otonashi that Naoi was with them in the Afterlife, or about the vigils set up after his death.
- You Are Better Than You Think You Are: When almost everyone had moved on in the last chapter, Yuri thinks that by doing so they choose Otonashi over her. Otonashi and Naoi respond by telling that she gave them a purpose when they arrived, and it was because of her kindness they took her last advice to make their own choice about moving on, but not before thanking her for being their Cool Big Sis. These words helped Yuri head to her next life.
