Mion Sonozaki appears in the non-canonical OVA series *Higurashi no Naku Koro ni Kira*, known for its exaggerated comedy and fanservice, differing from the main series. Within this OVA, she serves as a member of a cheerleader squad supporting Rika and Satoko in their magical girl battles against criminal organizations. Mion maintains her signature energetic leadership and competitive spirit, adapted to the OVA's lighthearted tone. She coordinates cheer routines and club activities, reflecting her established role as the games club president. Her design stays consistent, featuring mint-green hair in a ponytail, an athletic build, and casual outfits, though she wears cheerleading attire here. The OVA omits her backstory as the Sonozaki heir, her demon tattoo, and family responsibilities, focusing on comedic interactions. One episode features her in a Chinese-style red and yellow bathing suit at a beach, with the absence of her back tattoo explained as waterproof skin makeup for such events. Her personality emphasizes her cheerful and competitive aspects, without deeper character development or relationships beyond surface-level gags. The OVA excludes any horror elements, psychological tension, or narrative progression related to her background or future.