Brand: Tombow Pencil Co.
Made in: Japan
Wish I could say for certain, but these Mono 100's with JIS mark could date back to the early 80's.
This Japanese company was founded in 1913 and is still manufacturing fine writing instruments nearly 110 years later.
According to their website, “Tombow (tonbo) means “dragonfly” in Japanese and was often referred to as akizu/akitsu in ancient times. Since Japan was called Akitsu shima (dragonfly island in English) in the past, the name of the company also represents our desire to represent Japan's stationery industry.”