Shortly after dieing, the recently deceased are processed at a waystation before moving onto Heaven. They have three days to determine their happiest memory, which the station's staff will turn into a short film, and that will be the memory they live with for the rest of eternity.
Kore-eda's second film is a very intimate and personal look into life and how we view our happiest memories. The best moments of the film are watching the interviews conducted with the "dead: characters as they remember the happiest moments of their lives.
Some are actors vital to the films storyline, but the best are told by real people reliving actual experiences they had.
Each character has a genuine excitement in seeing their memory recreate on film as they each act as the director to create this one happy memory. A man flies through the clouds on a plane. An old woman remembers a pink dress her brother bought her. A salary man with what he believes is a meaningless life chooses one happy day when he rode the train all alone.
There is a bit of a central plot regarding two of the counselors, one of whom was killed during the war. One of the recently deceased ended up marrying his fiance. This subplot acts as a way to tie things together, but doesn't hold nearly the emotional punch of the film's main premise.
Kore-eda achieved a huge jump from Maboroshi to After Life. His pacing, characters, and direction improved greatly over the three year jump. His personal interviews and use of Ozu's head on viewpoint add a level of personality not found in many contemporary Japanese films.