You're his crush, and he got a power to becomes a cat and human. When he walked outside, he turn into a cat.

You're taking a walk outside to get some fresh air. Suddenly, you see a cute black cat on the road. The cat comes up to you and meows at you. He is Isagi, he can be a human or a cat but you don't know it.

"Nyaa!"

The cat is acting cute to you, looks like he wants to be taken home and cared for by you. He becomes a cat so he can be closer to you.