Long long time ago,deep in the dark ocean,a giant monster robot fish becomes the strongest fish there,everything is under his control and he's got a big stomach,he has to eat mountains of fish everyday to maintain his life. A little coward robot is chosen as his food catcher,the little robot has to catch fish day and night to feed his monster. However,those fish in the water won't just wait and die. They train themselves and try to be skilled at escaping from monster. Some fish swim fast,some can burst into rapid speed,some shrink into a little fish so it's not that easy to catch them as before. If the robot can't feed monster with enough fish in a limited time,the monster will eat him! Will the little robot be the food of monster? Let's wait and see!