Komajiro is a komainu yo-kai resembling a shiba inu, sporting ochre fur with a cream muzzle and stomach patch, darker ochre inner ears and tail, light blue eyes, and brown swirls on his cheeks and hips. Characteristic long, brown, flaming eyebrows resembling hitodama flames frame his face, and he consistently carries a blue pouch adorned with swirl patterns. Like his twin brother, he assumes a human form by placing a leaf on his head. Komajiro embodies curiosity and optimism, adapting more readily to urban life than his sibling, which sometimes sparks jealousy. This adaptability includes mastering city slang, modern technology like smartphones, and pursuing a DJ career under the alias "KJ" at a nightclub. Despite these modern pursuits, he deeply admires and respects his older brother as an inspiration. His signature catchphrases are "Oh my swirls!" and "Mongero!". Originally part of a komainu statue pair, Komajiro is the younger twin brother of Komasan, both over 300 years old. His initial story involves searching for Komasan after the latter departed their rural home for the city, culminating in their reunion during urban adventures. They now share a small house, frequently exploring the city and beyond. A distinct Shadowside incarnation presents an alternate origin: once a frog living at a shrine, he was crushed alongside the dog Nobushige under a guardian statue due to accidental magic by Mitsue Arihoshi. Reborn as a yo-kai and named by Nobushige (who became Shadowside Komasan), this version possesses a strong sense of justice while overlooking his own suspicious traits. After hibernation post-rebirth, reawakening leads to reunion with his Komasan and involvement with the Yo-kai Detective Agency, resolving past grievances with Mitsue and gifting a Keystone to Summer. He harbors an inherent animosity toward snakes, prompting immediate conflict with Sly. His abilities include electrical manipulation in games, manifesting as lightning bolts and techniques like "Lightning" and "Wild Zaps," though this trait is absent in anime or manga. Inspiriting humans causes difficulty locating sought items. His "Omega" skill boosts strength when adjacent to Alpha-aligned yo-kai, while inspirits like "Tiger Power" enhance ally speed. As DJ KJ, his abilities shift to support; "Feel da Beat!" and "Scratch My Swirls" raise ally stats through music, and "This is My Jam" provides minor all-stat boosts. He evolves into Komiger at level 33–35 across games or via fusion with a Swirly Soul in spin-offs. Key relationships feature an unwavering fraternal bond with Komasan, mutual maternal affection for Koma Mom, and camaraderie with human protagonists like Nate and Hailey Anne. The Shadowside iteration shares an equally strong connection with its Komasan counterpart. Narrative development spans rural displacement, urban integration, professional pursuits like DJing, and interdimensional conflicts. Shadowside arcs explore themes of reincarnation, unresolved mortality, reconciliation, and integration into detective work.