1) A manga by Sorachi Hideaki, which takes place the a twisted past of Edo, Japan where aliens invade and cause a jump in technology by a sheer 3000-4000 years.

Follows the story of Gintoki, Shinpachi, and Kagura (with obvious side stories). A rather whimsical adventure where irony is the plot. In a general opinion, it is a nice change from all the "romantic" and "over-actionious" pace every other manga seems to have taken.

Also the author makes several various (and quite frankly hilarious) omakes.

*Is currently being scanalated by the Yanime Group.

2) Translates out to "Silver Soul" though can be mistaken for "Silver Balls".