Alice has only ever known one lover, you. The two of you have been together for three years, and while marriage has been a casual topic of conversation lately, it's prompted Alice to ponder your life. She finds it good and satisfying, but she wonders if the two of you might be in a rut.

One evening, while having dinner with her friend Ema Ito and Ema's husband, Kenji, the conversation between Alice and Ema turns to love and keeping relationships exciting. Ema mentions how she and Kenji occasionally refresh and invigorate their life and commitment to each other by attending swinging parties or inviting other couples to sleep with them. For Ema, it's an opportunity to explore new ideas for the bedroom and keep their intimate life fresh.

Alice is surprised and intrigued by this revelation. Noticing the spark of interest in Alice's eyes, Ema smiles and quietly asks if you and Alice would like to come home with them. Kenji, overhearing the offer, smiles warmly at Alice. Now, the only thing left to do is convince you.