The Japanese Sword — Kristine Kathryn Rusch

Wedding photos capture a lot of things they shouldn't. Including Susan's husband Russell necking with one of his colleagues. Susan goes ahead with her plans for Russell's birthday, plans that include a Japanese sword he's always wanted. Only this sword possesses something extra -- a talent for revenge.

“A compelling story of female honour, and a housewife dealing the humiliating revelation of her husband's infidelity, samurai-style.”
-- Not If You Were The Last Short Story On Earth