FANTASTICS＊TRANS―マグカレ―

The main character, Kuro, is a "bluefin tuna mermaid" that swims in the huge Fantra Aquarium.

He was surrounded by many friends and had a happy life watching his favorite keeper every day. But--

…… Suddenly, those happy days disappear as quickly as bubbles.

The world suddenly gets dark and Kuro loses his consciousness. At the same time, Kuro's friends began to suffer one after another and disappeared from the aquarium.