Meitantei Conan S19E26 - A House in the Aquarium

Professor Agasa and the Detective Boys visit an aquarium designer named Nishida at his house. Once at the house they knock on the door waiting to be let in. Strangely there is no answer and they are let in by one of the neighbors named Kosuke Imura. The Detective Boys then find Nishida dead in his bathtub.