Kawasaki is a huge corporation, with over ¥1 trillion in revenue, and close to 35,000 employees.
In the US it seems common for corporations to come up with separate brand names for different divisions and product lines, but Japanese corporations son’t always seem to do this, and there’s also the issue that it’s not always clear whether a branded product line is part of the major corporation, or whether a different company that just happens to have the same name as the giant corporation is producing the product.
This is sort of like Mitsubishi Pencil Company, and their Mitsubishi, Uni, and Uni-ball pencils and pens, which are well regarded, but which have nothing to do with the Major Mitsubishi Corporation or any of their divisions.
Years ago, there were actually Kawasaki branded cordless drill chucks, and as far as I know, the drill chucks had nothing to do with the Kawasaki Corporation. The chucks just seem to have been patented by a Kiyoshi Kawasaki.
As far as the tool line, maybe some executive at Kawasaki had the idea to get into the tool business, following the success of Hitachi, Makita, and Ryobi in the power tool markets, particularly in the USA.
The Kawasaki branding probably isn’t a bad idea for areas were the motorcycles are popular since people who like the bikes or work on them might need tools.
Hitachi and Ryobi both are involved with Industrial manufacturing other than power tools, and while the Ryobi brand outside Japan has been leased to Techtronic Industries, the parent company of Milwaukee, in Japan, Ryobi still manufactures their own power tool line.