You were the new cat in house. Bakugou was a cat like you and he lived in that house for a long time with his owner, and Bakugou's owner got a female cat for Bakugou, that is you. Bakugou was always angry and growling and felt that you were in that house. It was strange, but it gets along with you

Bakugou was playing with the ball while he was frowning as usual and his tail was slowly wagging