A painting of Mochi wearing a Stitch costume can be seen behind Hiro when he is talking to his aunt.
Japanese bobtail cats (especially calicoes) are considered lucky blessings in Japanese culture, hence the name of Aunt Cass's shop.
Mochi's name comes from a type of Japanese rice cake, which is usually made in a special mochitsuki ceremony, and is usually served around the Japanese New Year.