The underground platform at Cosmosquare Station on the Chūō Line (July 2014).
The station opened to rail traffic on December 18, 1997. The name "Cosmosquare" was selected in a public poll conducted in 1988 for residents of Osaka, relating to the development of "Techno Port Osaka" on the artificial islands of the Osaka Bay area.
On July 1, 2005, Osaka Municipal Transportation Bureau took over management of the station; Osaka Metro would take over management of the station on April 1, 2018.
A mini aquarium was installed on the subway platform at one time. Due to excessive maintenance costs and the relatively few users of the station, it was removed.
A different train approach melody was used on the station, playing a sound similar to that of an ocean wave. On March 27, 2007, the melody was changed to the standard approach melody that is used on the metro.
A potential extension to the artificial island of Yumeshima was first discussed in the 1990s as part of Osaka's failed bid to host the 2008 Summer Olympics. The Yumesaki Tunnel, which opened on August 1, 2009, was built with space for the Chūō Line to extend westward to Yumeshima (this segment now called the OTS North Technoport Line [ja]), which is now expected to be completed in 2024 in time for Expo 2025 to be held at said site.
