Hagoromo is a university student. She has a mysterious special ability which allows her to travel back in time when she gets soaking wet. She lives with her older brother Junnosuke and her father Shingo at a love hotel, which her father runs. Her brother Junnosuke runs a private detective office out of a room in the love hotel. He isn't particularly good at his job and he always asks Hagoromo to go back in time to find out the truth.
