Asō (麻生, Asō) is the butler of Akiko Tani.
Aso is a very slender man with pale skin, gray hair, and a thick gray mustache. He is only ever seen in his butler attire which consist of just a tuxedo.
Aso has shown to be a very loyal person, as shown when he had kidnapped Akiko on her orders. He also is shown to care a great deal for the family, as he had shown great concern when Akiko had actually been kidnapped.
The Kidnapping of the Company President's Daughter Case
Main article: The Kidnapping of the Company President's Daughter Case Aso is first seen at the house of the Akiko family where he gives Kogorō Mōri, the private detective Akiko's Father hired to find his kidnapped child, a description of what had happened during the kidnapping, as he was the only who bared witnessed. His story is soon figured out by Conan, and then eventually Kogoro, stating that his story didn't hold up and figuring out that he was the kidnapper. Then another man calls, stating that he was the actual kidnapper, who demanded 3 million yen for her return.
They eventually find the kidnapper, after Ran Mōri had knocked him out, with the revelation that no one expected which was that Akiko had pretended to be kidnapped so she could spend more time with her father. He forgiven by Akiko's father, and was ordered to make plans for him and Akiko to spend time together.
- His kanji "麻生" can mean "Aso Faction (of the LDP)".