Ai no Joou: Butai Joyuu Satsujin Jiken

Riko adores the talented stage actress Katzuki Ichie, who is best known for her performance as "The Indigo-blue Queen," a noble woman who is poisoned. However, Ichie is worth more to some people dead than alive, and she's been receiving anonymous death threats. When the curtain falls on the final show of "The Indigo-blue Queen," Ichie dies as the cryptic threats foretold, and everyone—including Riko—is suspect...!? (Source: ShoujoMagic) Included one-shot: Private Room