Mitsuo (played by Shunsuke Kazama) is determined to become a boxer, and has devoted all his energy and time to this, hoping to win the glory of the world champion one day. One day, Mitsuo's brother (played by Tsuruno Tsuyoshi) entrusted two kittens to Mitsuo for care, one of which was named Xiaohei and the other was called Xiaoji. Mitsuo, who was devoted to improving his boxing skills, had never had the experience of taking care of small animals, so at the beginning, he was completely unable to adapt to the addition of these two "little troublemakers" in his life. However, as time went on, and with the help of "cat scholar" Xiaomei (played by Matsuoka Moyu), the relationship between Mitsuo and the kittens became closer and closer. In a game, Mitsuo was accidentally injured. This serious injury made it impossible for him to continue his boxing dream. In an instant, Mitsuo's life lost all hope and meaning.