Padak -2012- 〈PREMIUM — 2027〉

The tank is a grim, brutal place — fish are routinely taken out to be killed for customers. Padak trains and bides her time. The climax involves a daring leap from the tank during a moment of chaos.

It seems you’re asking for the story of the 2012 film Padak (also known as Padak: Swimming to Sea or A Fish Story in some English releases). padak -2012-

The film is a dark, mature animated feature about hope, despair, the instinct for freedom, and the brutal reality of the food chain. Despite its cute character designs, it deals with death, survival, and hopelessness. The tank is a grim, brutal place —

Here’s a summary of the plot: