1000 Yen brown, green serial

The Natsume Soseki 1000 Yen ran for a remarkably long stretch given Japan's printing bureau was simultaneously developing the more sophisticated 2004 series, which would introduce the microprinted security upgrades and new color-shifting ink that finally replaced it. By the late 1990s this note was circulating alongside early intaglio-heavy issues from other major economies, and Japan's relatively restrained security specification drew notice from counterfeit analysts — the thread and watermark combination was considered thin protection for a denomination of this value.