Mikan was not always called Mikan; before meeting Tom, he was left in a box with his siblings by their birth parents. An elderly gentleman discovered them and took them in. During this time, Mikan learned how to communicate like a human and walk upright, but also realized that not all people would accept or comprehend a talking cat.
Mikan is generally cheerful and enjoys teasing Tom, yet he possesses an artistic side as well. He has a tendency to get drunk and reminisce about his beloved old man. Additionally, Mikan can be quite emotional when it comes to family love. Sake is one of his favorite drinks.