Butler Saionji's Great Reasoning

In "Butler Saionji's Great Reasoning", a perfect servant named Hajime Saionji works for an elegant madam. This curious mistress has a pure and innocent personality. When her husband died, Hajime and the mistress had a very deep bond. However, behind Hajime's perfection, there is an unsolved mystery. Intrigued by the truth behind the death of the madam's husband and Hajime's secretive life, we will be invited to solve this interesting puzzle.