Meet Setsuna. She's cute, sexy, and deadly. When she's not out murdering people as a professional assassin, she's nesting at home, trying to adjust to a domestic life with her new husband. She skewers ingredients for dinner, draws a knife on unwanted solicitors, and sleeps with one eye open, just in case enemies sneak in. Her lovestruck husband doesn't ask her a lot of questions about her day job, so this arrangement can work if love conquers all, right?