If you’ve ever bought an inexpensive small plastic bento box at a 100 yen shop or via eBay, the chances are pretty high that it was made by one company, Nakano Co. . They are the ones responsible for the bento boxes carrying the mysterious Lube Sheep logo. After visiting their company web site, I still have no idea what it actually means, and it probably doesnt mean anything at all - it’s just a cute piece of Japanglish that someone in the company thought sounded good. (Yes, I know it sounds a bit dirty, but let’s try not to go there.)
Nakano makes the puti fresh, Clickety Click and URARA lines under the Lube Sheep brand. All items are 100 yen per piece or set in Japan, and are usually sold for around $1.50 in U.S. Asian dollar stores (like Daiso and Ichibankan), and slightly higher in Europe. Besides bento boxes, they make chopstick sets, bento bags, and various accessories, such as this Clickety Click onigiri mold set.
I have two Lube Sheep bento boxes myself. The 2-part blue tombo or dragonfly one (pictured in detail on this page ) is one of the workhorses in my arsenal. It appears quite frequently on Just Bento.
Nakano also makes a line of higher end (or more expensive anyway) products under the Bay Asuka label. These have more grown-up designs.
You can check out their current product lines on this page  (in Japanese). Click on each product picture for a bigger view and prices in yen. Besides bento related items, they also make plastic lunch sets for kids and the like, which don’t seem to get sold much out of Japan. But they are cute and cheap so maybe the Asian dollar stores will start selling them if there’s a demand.
If you don’t have an Asian dollar store or 100-yen shop near you, you can find Lube Sheep and Bay Asuka products from eBay merchants (check this page  for continually updated listings of bento-related items on eBay). J-List  also carries them, though usually in sets like this cute yellow puti fresh set .