JIS – or Japanese Industrial Standard – is a Pacific Rim standard used for “Philips” (cross, star,) type screwdrivers. Most people, professional mechanics included, don’t even know that such a thing exists. But every “Philips” screw on a Japanese vehicle is not a Philips screw at all, but a JIS screw. They can be identified with a small dot on the top of the screw:
Philips screwdrivers don’t fit JIS screws, at least not properly. Because they don’t fit all the way into the screw, you tend to mangle the screw when attempting to tighten it, or loosen a tight one. If you have any “Philips” screws on your Japanese bike that are stripped or mangled, this is what has happened. The solution? A set of JIS screwdrivers.