Need long sleeved clothing to protect against sun in humid climates

I am in Japan and it really gets humid here during summer. I go on a lot of hikes on paved roads or out in the country with no cover. Is there any type of cool, light long sleeved clothing specifically designed for this? Gloves to protect the back of my hands would be nice too.

There are several companies that make clothing that is sunblocking and breathes fairly well. But it is fairly expensive. A less expensive way to go is to use long-sleeve Coolmax (or similar wicking) T-shirts. If you aren't too style conscious, you can use lightweight longjohn tops and bottoms, with a pair of very light nylon shorts for modesty (like most of us dirtbag backcountry types - hey, there's no one else out there but other backcountry types, so who cares about style). Another alternative for the pant part is some of the very light Supplex or similar materials in pants.

The old standby for hot, humid climates is loose cotton clothing. The biggest problem with cotton for outdoor use is that it holds water, which is a disaster in cold weather - leads to hypothermia very quickly. But in high temperatures, this isn't a problem, and in fact holding the water is a bit of a virtue in that case.

A wicking broadbrim hat is also a good thing. There are hats sold in Japan (since you say you are there) that are very lightweight, designed for exactly the conditions you describe.