Aria the Origination: Sono Choppiri Himitsu no Basho ni...
English name: Aria the Origination Episode 5.5: That Little Secret Place…
Genres: Comedy, Slice of Life
Type: Special, Episodes: 1
Aired: Jun 25, 2008
Studio: Hal Film Maker
Source: Manga
Rating: G - All Ages
Synopsis:
Special episode based on manga Navigation 39 entitled "The Secret Place". Its action takes place between episodes 5 and 6 of Aria the Origination.

Akari and President Aria take a walk in the eastern part of Neo-Venezia. The are spotted by Akatsuki, who follows them to try to greet Akari. They eventually end up at St Mark's Basilica, where Akari has a secret place, which is discovered by Akatsuki, Aika, and Alice. 

(Source: Wikipedia)