What is the radius of the incircle of the triangle in terms of the radii of the three “kissing circles” of the Malfatti problem (see, e.g. [url]http://ggbtu.be/m593233[/url])? This problem was proposed by the Japanese mathematician TAKATADA Shichi on a sangaku (算額 mathematical tablet hung on a shrine or a temple as a kind of offering) in the Meiseirinji Temple (明星輪寺) in Ogaki City (大垣市).