Genji was a mer, one of the long-finned dragons that were common around Japan, but he had been a part of the Shimada Clan, a group of these creatures renowned for their aggressive and demanding interactions with humans, having long been revered by the village of Hanamura in the past. Now, however, the Clan was thought to either be extinct, or driven away by hunters.
He was left for dead by his brother, but had been picked up by a couple of fishermen that found him. He thought he was going to be brought somewhere where he was going to be patched up and then released back into the sea, but apparently not. Instead, he ended up in a lab, constantly being poked and prodded for tests, mentally breaking him and cybernetically rebuilding him to the point where he would be rejected by his own kind.By the time he managed to escape he was broken, aggressive and hyper-protective over himself, refusing to let anyone near him. Well, except for one person - Gabriel, the person that had freed him.
He ended up found by the Aquarium institute, taking him in because of his malnutrition and aggressive behaviour, being put into a large tank so that he wouldn’t hurt anyone else. He had been angrily swimming in circles, stressed and wanting to be literally anywhere else. He didn’t know his environment, he was surrounded by strangers, and it all reminded him far too much of the lab he had been kept in before.
He perked up when he saw the door leading to the stone walkway surrounding the open-air part of his pool/tank, letting out a small noise when he recognized Gabriel being led in by a Keeper at the Aquarium. He dove off into the water, then launched himself at Gabriel when he was within reach, curling against him despite dwarfing the human by a good two and a half meters, growling at the Keeper.