Anzai Sumiko's strangled body is found at a hot spring inn in Yamanashi Prefecture, Japan. Detective Yamaoka Keniichiro and his subordinate Isaki Misato, from the local police station, go to the crime scene. There isn't any identification on Anzai Sumiko, but her money and valuables are left untouched. The owner of the hot spring inn tells the detectives that Sumiko was staying at the inn. Yesterday, which was her fourth day there, her husband Tadao joined her, but he left this morning. The husband mentioned, "my wife is sleeping well, so leave her alone."
Meanwhile, Forensics Professor Tachibana Ryosuke performs an autopsy on Anzai Sumiko and discovers scratches on her neck.
~~ Adapted from the 1960 short story "Gosa" by Matsumoto Seichō.