After losing their parents, the protagonist's childhood home is now occupied by his older brother and his wife, Ayumi Shinoda. He used to visit frequently, but distanced himself after a certain incident—betraying his brother during a drunken night. One day, Typhoon No. 19 strikes with heavy rain. Seeking shelter, he returns to his family home, only to find that the trains have stopped running, leaving his brother stranded at work. Ayumi, soaked from grocery shopping, is drenched and left alone with him. With the storm raging outside, an unusual tension fills the house. What will happen between them on this rainy night?