Suzuki had an OEM mag tank bag with the Kanji symbol on it. Nice bag, low profile and expandable.
I don't think they offer the Kanji version anymore, but the GSXR, Suzuki or just plain bags are still sold.
Removable map pocket on top, small zipper pocket at front, mesh zipper pocket inside. Comes with strap for securing to bike for added security, but I think I would fly off the bike before the tank bag would.
I had a Tour Master Mini Mag bag and Marsee before. Mini bag was too small, Marsee was too bulky (but roomy). The one from Suzuki had the lowest profile compressed, yet still plenty of room for essentials for the road and/or a stayover. When expanded, I could actually fit a jacket in it or jeans shirt and tennis shoes. Check out this link to the Suzuki site:
Suzuki Tank Bags