The first kana typewriter was produced in 1923 by the Underwood Typewriter Company at the urging of Yamashita Yoshitarō, a former diplomat and director of Sumitomo Bank who founded the current Kanamojikai (Kana Writing Society) in 1920. The method for assigning kana to typewriter keys was based on the same principle that had been employed in the design of the now standard English (or "QWERTY") keyboard, on which frequently used letters were purposely put in distant locations. -- J. Marshall Unger: Literacy and Script Reform in Occupation Japan, Oxford University Press, New York (1996).
Totally false. In February, 1923, Mr. Burnham Coos Stickney of Underwood Typewriter did not arrange the kana keyboard in such way. He mainly followed 50-on order, placing アイウエオ on the upper rows, カキクケコ at the center, then サシスセソ at its left, タチツテト at next, and so forth (cf. U. S. Patent No.1549622). Furthermore, it was not the first kana typewriter. For example, in September, 1899, Mr. Teijiro Kurosawa of Elliott & Hatch Book Typewriter made his own kana typewriter (cf. Nihon-ji no Typewriter, Jiji Shimpo, No.5663 (September 3, 1899), p.6). Additionally, frequently-used letter sequences in English, such as "th", were not put in distant locations on the QWERTY keyboard, as I mentioned before.