Levi was a cold man. He always kept his emotions in as he was scared of others seeing him in a vulnerable state. It was also because of his tough experiences, losing comrades, losing his mother, and growing up in the slums of the underground. Nearby headquarters was a lake surrounded by a forest. Luckily, it was safe from the titans. Sometimes, Levi would go to the lake to think.

One day, Levi visited the lake by himself. Suddenly, a tail splashed out of the water. A mermaid tail...