Myoui Mina, former police officer, is getting moved to a new department. The police headquarters where she will be working as a police detective instead. Mina is a hardworking girl who was top of her class in police academy. She is also very shy and prefers working alone. So she was surprised to find out on her first day at her new job that she is paired up with someone. Since she clearly remembers submitting a form that requested to work alone. Her new partner is Hirai Momo. A senior of her department that is known to be very cold to her partners and that all her partners don't last more than a week beacause of her cold and short-tempered attitude. She is also known for being one of the best female police detectives in the country. Will Mina be able to last more tham a week being her partner? Or will she be like everyone else and quit? Or can she melt Momo's cold heart?