The Yamadas and Chi move to a new apartment house, where keeping a pet is allowed.

This is the story of the main character living together with a mysterious mini middle-aged man.

One day, a small kitten named Chi is found by a young boy named Youhei and his mother. They decide to bring her back to their home to live with them despite their apartment's rules against keeping any pets. Chi, Youhei, and Youhei's parents cherish their time together as they make new friends, good memories, and have fun times together. These short adventures revolve around the daily life of Chi and her family, in addition to the many friends that they make along the way. No matter what trouble Chi ends up getting into, she knows that her family will always love her!

Unaired anime bundled with the limited edition of the 9th volume of the manga.