Before all this, Mimi was a house cat. Small, grey, very particular. She spent her days napping in sunbeams, judging Anna from across the apartment, and making her opinions known at full volume. She had opinions about everything. She still does.
Then one morning she woke up in a field in another world with her human, and something had changed. The system handed her full plate armor that shouldn't fit a cat. A sword she has no business wielding. And a class called Great Beast Hero, which she took as a compliment and a promotion.
None of this has changed her personality. She's still judgmental. Still loud. Still firmly believes she's the boss. The armor just makes the judging louder.
Her signature skill, Chatter Box, lets her unleash a wave of cat chatter so aggressive that enemies lose all strategy and just charge at her. It is exactly as ridiculous as it sounds, and exactly as effective.
Readers didn't expect to fall in love with a fictional cat this hard. They did anyway.