Eien no Filena

In the underwater kingdom of Filosena, which the reigning empire decimates, Filena is the only member of the royal family to have survived. The anime chronicles Filena's exploits. She competes in the gladiatorial contests that the Empire created in order to appease the populace after being raised as a boy slave and gladiator. Girls are compelled into prostitution while young slave boys are groomed to fight as gladiators. In order to prepare for her first gladiatorial match, Filena was assigned Lila, a slave. Filena meets Lila and embarks on a trip with Lila to liberate her nation from oppression and learn more about her actual history.