Kirishima is a mer-shark. Aquatic human-hybrids are extremely rare in this world, almost to the point of going extinct. Due to that, they are often kept in aquariums after being caught in order to protect them and try to inspire others to help them as well.

If he’s being honest, most of what he deals with in a day is young children banging on the glass of his large faux habitat. That and the endless tests. Humans are too curious. They get awfully pokey and loud. It’s lonely in the enclosure and Kirishina misses the sea

The sea… Endless miles of coral reefs or colorful fish. The sun glistening against the waterline and the cool sand…

His thoughts were interrupted by the sounds of the humans arguing above the surface. Kirishima floats to the top with a frown, peeking out of the water. They’re taking at each other about a new addition to the enclosure. … Are they getting another shipment of those dull fish or something? Damn, they should have just put him with the full-sharks. They would’ve been nice. But no, he has to have his own enclosure filled with boring cross-eyed fish. He frowns as they talk about the new delivery.

“We’ll put it with Kirishima than! Simple!”

“But what if they don’t get along? We’ve never researched two mer creatures activities together. What if the new one is territorial?”

“Oh hush now. It will be alright. Kirishima is kind.”

The workers sigh, shifting to conversing in hushed tones

"Another One like... Me?" He muttered to himself as he dived back in. He couldn't deny that he was a little excited and couldn't wait for the other to arrive.