Hinata Rin is Hinata Ema's Adopted Big sister. She spends her life in her dark and isolated room and avoided talking to people, including her little sister. She works as a Detective and is a Specially Designated Minor. Her intelligence is way out of reach that kept herself isolated from other people for some reasons. One day, She learned that her adoptive father will be married a Middle aged woman with 13 sons and is Going to live with them. How could she cope up from it considering her condition? Will something change inside her? Or things will be just the same?