Kim is forced by her dad to join a club for small children that he leads, much to her dismay. Meanwhile, Monkey Fist plans to steal a very special monkey to fulfill a prophecy.

When a diamond is stolen, all the signs indicate that a Lithuanian Wolfhound breeder named Falsetto Jones is the thief. Kim and Ron enter Rufus into a dog show as a Peruvian Hairless in hopes of confronting Falsetto and getting the diamond back, though will Rufus actually be able to play the part?

When Middleton High School participates in a student exchange program, Ron is selected to go to a school in Japan while a student named Hirotaka is chosen to come to Middleton. Ron finds out that the school he was assigned to visit is a secret ninja school while Kim and Monique eventually start crushing on Hirotaka. However, when Lord Monkey Fist steals the Lotus Blade from Ron’s sensei, it’s up to Ron to save the day; though without Kim’s help.

When Mrs. Hatchet discovers that Kim has an overdue library book, KP's cheerleading activities are suspended. Ron realizes that he lost the book, and he has to retrace his steps through the last few missions he and Kim went on to save Kim from...library lock-up!

Yori’s sensei has been kidnapped and all evidence indicates that Lord Monkey Fist is responsible for it. Yori comes to Middleton to get Ron, in which Yori and Ron head off to South America to attempt to stop Lord Monkey Fist. However, when Kim starts to grow suspicious about Yori’s sudden appearance in Middleton, she heads after them to get to get to the bottom of their predicament.

To prove a point, Ron decides to eat only Bueno Nacho. Meanwhile, HenchCo is holding an auction for a molecular transducer that Kim must stop.

Ron comes home to unexpectedly find his new adopted baby sister named Hana Stoppable in his room. At the same time, he has to take care of a sack of flour for health class. Meanwhile, Kim and Ron team up with Yori to stop Monkey Fist yet again.

After discovering Hana walking on the ceiling, Kim and Ron try to get to the bottom of Hana's secrets. Meanwhile, Monkey Fist finds an ally in Yono the Destroyer as he continues his search for the "secret weapon".