''Tristia Of The Deep Blue Sea'' is a {{PlayStation}}2 and PC game developed by Kogado Studio's Kumasan Team. The game is part of the Deep-Blue series along with the sequel, ''Neosphere of the Deep-Blue Sky''. Released July 20th, 2002 for the PC and March 25th, 2005 for the PS2.

Following the production of the game two novels were produced (coinciding with the two release dates for PC and PS2). The first was written by Syogo Mukai with illustration by Eeji Komatsu and published by Enix on November 15th ,2002. The second written by Takashi Aki and illustrated by Kawase Yuki was released by Media Works November 10th, 2005.

Along with the game and novels a {{Manga}} was also produced. ''Aoi Umi no Torisutia ~Nanaka no Hatsumei Koubou Nikki~'' was written by Sakuya Yuki and published by Media Works in Dengeki Daioh magazine. Starting publication on October 27th, 2004, the Manga is ongoing, currently culminating in one volume.

Additionally, an {{OVA}} was produced based off the work. Directed by Hitoyuki Matsui for the studio Ufotable Zippers, the two episode OVA was released May 21st, 2003.

All incarnations involve the plot of the beautiful seaside town of Tristia, which had fallen into ruin and decay following the invasion of dragons ten years prior. Unable to rebuild their town the villagers sought out a famous inventor for aid, instead however the inventors granddaughter Nanoca Flanka arrived taking it upon herself to spearhead the reconstructive efforts.
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