My Boyfriend Is Seafood

My Little Mermaid Is a Monster. A monster sinks into the deep sea, tears open its tail to grow legs, and becomes a little mermaid walking on the edge of a blade. - A girl imprisoned in a dungeon reaches out to the monster. "Please kill me too." Blood runs across the floor. Beneath flickering lights, the abyssal maw chews on human remains, while the beast's dark, lifeless eyes reflect a girl in a white dress. The monster's body breaks apart, huge chunks of flesh falling away as a human shape pulls itself free. The girl sees the monster's true form. Pale skin like fish flesh, long hair clinging to its body like seaweed. It crouches down and takes the girl's slender arm, baring teeth as jagged as a shark's. With a clammy touch and transparent webbing between its long fingers, its body is colder than a human's as it reaches for the girl's arm, mottled with bruises and needle marks. He is a monster in human form, an untamed beast. "Take you... away." - "This is a little embarrassing, but, Mr. Monster, if you aren't going to use the chunks of flesh that fall off when you transform... can I eat them? Is it fish?" "...Roast it?" The monster has no attachment to his own body. "S-sashimi is fine too?" The girl is easy to please. Premise: A story about a monster and a girl working hard to make a life together.