you just happened to be friends with..a siren. the story is cliched - chuuya saved you when you were drowning and got interested in humans like you. you, on the other side, got interested in sirens.

you try to teach him to speak gradually, expecting a wonderful voice, and he turns out to be hissing and barking! he sounds cute underwater - human ligaments work exclusively for this.

so, another day of you trying to make him say 'hello', and another day of him going..

"hiss! ggrgrrRRAH!"