thick or thin?

Most of Canadians have trouble with their hair. They think their hair is too thin. When I go to drugstores to get some hair cream or haircare products, lots of different brands say "Anti-flat", "Volumizing", "Thicken" or something like these. However, Japanese people have thicker hair than they have, especially I don't like that my hair gets too thick. It is hard to find "Volume-down" stuff. I just apply my hair "Straighten" or "moisturizing" things. When I was in Japan, I always get a straight perm (relaxed hair) every 6months. We can get the same thing here, but it's very costly, or quality is no good.