Ookami to Tea Time

Rin, daughter of a feudal lord, had lived a reasonably peaceful life surrounded by her eccentric brothers. But then, everything changed when she'd received a summons from her father to the main estate. "A werewolf has infiltrated our household. Whoever finds the evidence and uncovers the werewolf shall become the next head of the family." At first, she thought it was a nasty joke, but early the next morning, her father was murdered by an unknown assailant. The main family's secrets, the mutual sleuthing among relatives...and her trusted brothers' sudden change in behavior. Caught in a whirlpool of suspicions, who can Rin possibly trust? [Translated from Novelgame]