Original air date, December 13, 2010.
Tropes:
- Armor-Piercing Question: Nao asks if he really loves her. Haruka is unable to answer and returns home.
- Date Rape Averted: Haruka attempts to force himself on Nao but he stops when she begins to cry.
- Immodest Orgasm: Sora achieves one — just as Kozue and Nao burst through the front door of the twins home.
- Interrupted Intimacy: The Kasugano twins are in the middle of making forbidden love when they get caught by Nao and Kozue.
- Love Confession: That evening, Sora, with her fever subsided, confesses her feelings to Haruka and the two make love, beginning a relationship.
- Love Revelation Epiphany: It's after catching Sora masturbating and being unable to get her out of his thoughts that makes Haruka realize he feels the same way, much to his dismay.
- Making Love in All the Wrong Places: When the Kasugano twins get caught in the act by Kozue and Nao, they were having loud sex in the entryway of their house with the front door unlocked. What did they think was going to happen?
- Oh, Crap!:
- Kozue when she hears Sora's loud moaning coming from the Kasugano residence and realizes what is going on.
- Haruka and Sora, when they get caught having sex by Kozue and Nao.
- Properly Paranoid: After seeing Haruka and Sora spending so much time together in public, Kozue and Nao rent a book on the histories of incest between family members, fearing that the Kasugano twins may be getting too close. Turns out they were right.
- Retargeted Lust: Haruka hits his limit and tries to get rid of those thoughts about his sister Sora by taking Nao to a hotel, but she rejects his act.
- Secret Relationship: Haruka and Sora maintain their relations in secret due to the incest taboo.
