Boku no Kokoro ga Chuu to Naku

A man lives an ordinary life: he has a job, a family, and take care of his father. Excepted that his father is convinced of being a cat, and acts all day as such. This infuriates his son, not only because it is weird, but because it reminds him of when he was a child, when he was convinced of being a mouse. Unlike his father, he was able to fight his animal instincts and live as an human... really ?