Daikoukai Jidai Gaiden is a Strategy game, developed and published by Koei, which was released in Japan in 1997.

Uncharted Waters is a popular Japanese video game series produced by Koei as part of its rekoeition games. In East Asia, the series has a large cult following, but has not received much recognition outside East Asia. The series has been compared to Sid Meier's Pirates! in gameplay and theme. It is a simulation and CRPG series dealing with sailing and trading.

Daikoukai Jidai Gaiden is a side story released in 1997 on PlayStation and Sega Saturn after New Horizons, the game uses the same engine and focuses on the story of two characters instead, further expounding upon the loose plot that ties the series together.

In the games, the player takes up the role of a captain (also called commodore in some translations) and manages a seagoing fleet to participate in trades, privateering, treasure hunting, exploration, and plain piracy. Even though the series is largely open-ended, there is still a loose plot which requires the player to follow certain paths, and deviating from these paths may stall the progress of the story.

The two protagonists are as follows:

* Miranda Verte: Genoese adventurer who mistakenly thought the treasure hunter, Pietro Conti, had asked for her hand in marriage, and sets off to find him. Her quest eventually leads to a plot relating to an ancient civilisation in South America, which were touched on by Pietro's previous adventure.

* Salvador Reis: Pirate and adopted son of Hayreddin Reis (aka Khayr ad-Din). His adventure involves rising to fame as one of the Algerian pirates, compete for domination with enemy pirate clans and also struggle for power within his own clan.