"Angel Beats" is a Japanese anime series set in a purgatory-like afterlife where deceased students fight against a mysterious girl named Angel. The story follows Otonashi, a boy who wakes up in this world without memories and joins a group called the Afterlife Battlefront, which opposes Angel and seeks to understand their existence. The series explores themes of life, death, and the struggles of the characters, each with their own backstories and unresolved issues. As they confront their pasts, they learn to accept their fates and find peace, leading to emotional and poignant moments throughout the show.