Tantei no tantei (2015)

Overview

The cool, beautiful Sasaki Rena is the lone investigator who works for for a medium-sized research agency called Suma Research Agency. Because of her past related to her sister's death, she became a detective that investigates and pursues unscrupulous detectives. Her beloved younger sister was murdered by a stalker and she has been searching for the investigator who caused her sister's death in order to take revenge.