35. The Undelivered Letter

Keiko Kawasaki (Karin Yamaguchi) despises Yukiko Kawasaki, who lives in the same building. One day a letter addressed to Yukiko is delivered to Keiko's mailbox by mistake. Keiko sets out to deliver it, but just as she's about to press the intercom she overhears insults about herself, so she stops and opens the letter instead. It's from Yukiko's affair partner. Keiko hits on a plan for revenge...