They broke free of their nets and floated all the way to America. I'd never heard of these things before, but people collect them. We'd been looking for the perfect gazing globes for the window box, and then we noticed these things in the window of a cool store here in Madison called Unearthed. The floats themselves are more unoceaned than unearthed, though, don't you think?
Here's a blog about Japanese fishing floats.