Brand: Mitsubishi Pencil Co.
Made in: Japan
JIS 9800. Marked as modern since it has the word Matured vs Patented...working on a date for when that change happened. The extra kanji makes it more appealing in my view.
Founded in 1887 and formerly known as Masaki Yomato, Mitsubishi Pencil Co., Ltd. is best-known today for its uni-ball brand of quality writing instruments sold worldwide. Curiously, this Tokyo-based business is unrelated to Mitsubishi Motors and other brands within the Mitsubishi Group. Same name, same logo, completely different company.