Beniko presides over Zenitendō, a mysterious candy shop that reveals itself only to fortunate individuals seeking solutions. She possesses white or gray hair styled in a bun, bright red lipstick, and wears a kimono embroidered with old coin patterns. For each customer, Beniko selects magical candies precisely suited to address their underlying concerns or wishes. The consequences of these candies unfold based entirely on correct usage; improper consumption risks misfortune instead of granting happiness or resolution. She speaks in an old-fashioned manner, often ending sentences with distinctive phrases like "ござんす".

A black cat named Sumimaru assists Beniko within the shop, deciphering her subtle instructions and sometimes guiding customers to Zenitendō's door. This character maintains her consistent role across all documented media: the original novel series, the 148-episode anime television series, and the animated film *Fushigi Dagashiya Zenitendō: Tsuritai Yaki*, focusing solely on her shopkeeping duties.