Nagasato Daisuke is a 39-year old bachelor with an extremely negative attitude towards marriage. However, he truly believes that he'd rather be alone. Averse to taking the risk of bringing in other people into his living space, he protects it as if it was his castle, and is fully enjoying his idiosyncratic single life. Kumagai Hanako, on the other hand, is a 32-year old divorcee who works for a major trading firm. She has her own distinct thoughts about being single, doesn't want to get married again, and already planning for her life after retirement. When these two meet, they fight constantly, but they're actually similar in a lot ways.