The underground station is built on three main levels, with the Tōzai Line platforms located on the 2nd basement level and the Shinjuku Line and Hanzōmon Line platforms on the 4th basement level.
Platforms The Tōzai Line platforms consist of two
side platforms running approximately north–south. The Shinjuku Line and Hanzōmon Line platforms on the 4th basement level were originally configured as two sets of side platforms running approximately east–west parallel to each other. From 16 March 2013, the separating wall between these platforms was removed, allowing
cross-platform interchange between platform 4 (Hanzōmon Line Oshiage-bound) and platform 5 (Shinjuku Line Shinjuku-bound). The song "Under the Big Onion" (大きな玉ねぎの下で,
Ookina Tamanegi no Shita de) by the band
Bakufū Slump is used as the departure melody for the Tōzai Line platforms in 2015. File:Kudanshita Station-4.jpg|Tozai Line platforms, 2018 File:Kudanshita Station - 2024 Feb 16 various 13 15 30 247000.jpeg|Cross-platform interchange between the Hanzōmon Line and Shinjuku Line in February 2024 ==History==