A Kanji Numeral Converter With 小字, 大字, and 壱弐参 Legal Forms Japanese has three number systems: everyday kanji (一二三), legal kanji (壱弐参 — used on contracts to prevent forgery), and fullwidth digits (１２３). Converting between Arabic numerals and any of these requires handling place values up to 京 (10^16), grouping by 4 digits instead of 3, and knowing when to omit or include the leading 一. 1234 in