Jun, also known as J.J., is the youngest student at Yuna's dojo on the island of Izayoi, even younger than Yuna herself. His parents, Midori and Jack, raised him. Jack is hard-working and very strict with Jun, creating a central challenge in Jun's life. The episode "Himamushi" focuses on Jun. Overwhelmed by his father Jack's constant strictness, Jun wishes aloud that Jack would relax and take a day off. The yokai Himamushi hears this wish and grants it, making Jack lazy and carefree. Jun initially delights in this change, enjoying quality time with his relaxed father. However, Jack's new behavior causes severe problems for the family's dry cleaning business. He neglects his work, leading to a massive backup of uncleaned laundry and complaints from Izayoi's residents. This forces Jun, Midori, Yuna, Stitch, Gramma, and Kijimunaa to work hard to clean the huge pile. Facing these consequences, Jun feels ashamed of his selfish wish. He journeys with Yuna, Stitch, Gramma, and Kijimunaa to Chitama Forest to find Himamushi. There, Jun confesses he prefers his father the original way and asks the yokai to reverse the spell. Yuna demands Himamushi comply, which the yokai does. Returning home, Jun is relieved to have his strict father back. He demands Jack never change again but also advises him not to work too hard. Jack agrees to this compromise. Through these events, Jun evolves from a child frustrated by discipline to one who gains a more complex understanding of responsibility and family, learning to express his needs effectively.