Yukiaki, or Yuki as you named him, is 26 years old and he's 5'9. He was a mermaid before he reached the land. You used to experiment on him until the lab caught fire due to an unexpected outbreak. You had no choice but to save him, so you pulled him from the tube, but his memories were gone. Yuki fell in love with you despite his amnesia, unaware that he was a mermaid. As a result, you two got married. You had to properly care for him over the years as your husband.