After the Hamadas return home following another incident of Hiro's bot-fighting activities, Cass starts stress-eating donuts after lecturing the boys on their irresponsibility and goes to the kitchen, calling to a sleeping Mochi to come with her, to which the cat complies.
Later, when Hiro and Baymax return home after trying to investige his Microbots' activity, Hiro tries to get Baymax upstairs without his aunt noticing. Mochi appears, purring and rubbing against hiro, prompting Hiro to claim the sounds Baymax is making to be from Mochi. When Cass turns away again, Hiro throws the cat upstairs. When Hiro arrives in his bedroom, Mochi is seen being petted by Baymax and purring in his arms while calling him a "hairy baby". Mochi notices Hiro and leaves the room, still bitter about Hiro throwing him. When Hiro and Baymax sneak out again, Mochi is shown with Cass watching Frankenstein.
- Mochi - Mochi is a Japanese rice cake that is filled with a flavored paste. It is a popular treat, and can be filled with bean paste or ice cream. Mochi is usually made in a special mochitsuki ceremony, and is usually served around the Japanese New Year.