Beh Kawahara is a human-form black cat retaining animal features, characterized by long black hair to his neck and a distinctive central-parted white fringe framing violet eyes and lavender inner ears. He typically wears dark clothing. An X-shaped bandage on his left cheek sometimes flaps open, inadvertently generating portals to other locations, dimensions, or times. He usually remains oblivious to these events; noticing minor changes, he simply adjusts and reaffixes the bandage, reversing the effects.

His job assisting his newspaper delivery owner grants him extensive knowledge of Third Street's alleys and shortcuts. This role also causes his perpetually sleepy demeanor due to early mornings, which he dislikes but endures to support his master. His personality is easygoing and absentminded, often leading to distraction that frustrates characters like Bull. Despite this, he maintains a cooperative attitude and joins neighborhood activities.

In specific events, he participates in searches for missing companions, using his navigational expertise to guide others. During one search, he misinterprets "Waiha" as warm, comfortable spots like a wall perch or under a car. Nora intervenes for safety when the car poses danger, later correcting his understanding with a book. Beh accepts such guidance without resistance.

His relationships include a close bond with Bull, noted as "BFFs" in one episode title, and cooperative interactions with characters like Tora and Tama during adventures. He remains a supportive figure within Third Street, prioritizing his owner’s duties while engaging in group endeavors.