Kana and her brother were living together when his wife Himari joined them. Her brother was often away on business, so she was often alone with Himari. One day, despite being newly married, she discovered that her brother had been cheating on her. Himari was devastated, but Kana also found it difficult to talk to her about her brother. Eventually, she discovered that Kana's boyfriend had also been cheating on her with her best friend. The two consoled each other and quickly became closer...