At her farm, she grows many different kinds of crops, including carrots ("Pups Save the Bunnies"), apples and pumpkins (both in "Pups Fall Festival"). In "Pup-Fu!", it is revealed that she is the pups' Pup-Fu sensei and has a priceless antique scroll containing the secrets of the ancient Martial Arts Masters, which she inherited from her grandfather. She also recognizes that Marshall has a lot of hidden potential. When the scroll is stolen by the Kitten Catastrophe Crew and Mayor Humdinger, she appoints Marshall as the Supreme Protector of the Scroll and after the scroll is retrieved, she awards Marshall a golden belt.
Farmer Yumi is a hardworking farmer who grows food and raises livestocks (chickens, a cow, pigs, a goat and etc.). She cares greatly for her animals such as Bettina, Garbie and her chickens. She provides fresh produce for Porter's Café and presumably other establishments in Adventure Bay and elsewhere. She, Mayor Goodway and Chickaletta are good friends, the latter whom often hangs out on the farm with Farmer Yumi's other animals. She occasionally have the pups help her out on the farm. While she likes animals, she occasionally have trouble with local wildlife like when the bunnies invade her carrot patch ("Pups Save the Bunnies") or when Chompy the Beaver chewed up her barn when he was trying to rebuild his beaver lodge ("Pups Save the Beavers") and often have to call in the PAW Patrol to solve the problems they cause. Being a capable farmer, Farmer Yumi can tell what her animals like Bettina are feeling and knows when they are worried. In "Pups Fall Festival", she is alerted to an approaching winter storm by Bettina's odd behavior and explains to the pups that "Cows always know.", indicating that she uses Bettina's behavior as a sign of incoming bad weather. As a martial arts instructor, she is encouraging towards her students and believes that hard work and perseverance are just as important as martial arts prowess. She is also shown to be very perceptive as she reveals she was fully aware of the Kitten Catastrophe Crew's attempts to sabotage the pups martial arts routines, though this may also be due to her being aware of their tendency to resort to cheating to win.
Farmer Yumi has white skin with brown plaited hair that hangs down her back and brown eyes. She wears a tan cowboy hat, blue overalls, a green shirt, red and yellow gloves and brown boots. In "Pup-Fu!", she is seen wearing her white martial arts outfit dōgi.
Here are the attires worn by Farmer Yumi in the series: