Aria the Animation

Synopsis

President Aria leads Akari to a square with many cats, where she meets a girl wearing a belled collar who gives her a letter to deliver. In the morning, Mr. Mailman tells Akari the envelope contains an out-of-date format of video card but promises to locate the address for her. During gondola practice, Aria leads Akari to a canal she doesn't recognize, where the girl tells her the letter is important because it can 'overcome time and space' and deliver messages to the heart, before being called inside a house as Ami. Mr. Mailman tells Akari that the address is of an abandoned terraforming base out in the middle of the Adriatic. Woody, a sylph (airborne deliveryman), takes Akari on his sky-cycle to the base, where they find only a cemetery is above water now. They locate the gravestone of the letter's recipient and Akari plays the letter to it. The video is from a woman (with a cat named Ami) writing to her husband while he was away working on the terraforming of Mars, now called Aqua, and Akari recognizes in the woman's background the place she met Ami the second time.

(Source: Wikipedia)