Paul,
I did a little digging an noticed that in their early ads the HQ was in the Adachi-ku district of Tokyo. A little digging and their is a Sakae-cho (train station and possibly small inner town/community) in that same district. Albeit, Google Maps wasn't much help due to my inability to read any of the Japanese writing.
So there still may be a geographical relationship for the name Sakae.
Don
FYI: Sakae Ringyo Head Office was: 2-16 Aoi, Adachi-ku, Tokyo, Japan