Everything I see has a "uni" wordmark for the pencil company. However, AIUI mitsubishi more or less means "three rhombi" -- the companies are both named after the same family crest.
I felt like kind of a numbskull when I made the observation that "Asahi" must be a similarly diversified company (Asahi Pentax cameras, Asahi beer) and was informed that "Asahi" means morning or rising sun by some patient soul.
It happens everywhere: Ford's Theater (Washington DC) is not related to the Ford Theater (Utah); similarly unrelated to Ford Motor Company, Ford Instrument Company, or Ford Meter Box Company.