Ternion is a shi-fi action/rpg game, takes place in the year 2142, you are a Soldier of !DTA organization. One day, Desert, the capitain of Ternion and leader of !DTA, gets accidentally infected by a virus, created to provide better performance in battle, it was still a prototype and they discovered that causes the destruction of brain cells, and thus leads to madness. His madness causes him to desire the destruction of every lifeful planet of the galaxy, so you, Fushiko and Yuki, start to rebel, going to any length to stop him and save the entire galaxy from a bad fate.
Actually on Ternion you can find a known warm ocean-world exoplanet, that is called "Pan II". (Spoiler?)
The model of the "submarine" will be changed in near future.