Question: Information:  - The , also known in Japanese as for short, is a major private railway operator and land developer in the Greater Tokyo Area of Japan. Its headquarters are in Shibuya, Tokyo.  - Tokyo, officially Tokyo Metropolis, is the capital of Japan and one of its 47 prefectures. The Greater Tokyo Area is the most populous metropolitan area in the world. It is the seat of the Emperor of Japan and the Japanese government. Tokyo is in the Kant region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Formerly known as Edo, it has been the de facto seat of government since 1603 when Shogun Tokugawa Ieyasu made the city his headquarters. It officially became the capital after Emperor Meiji moved his seat to the city from the old capital of Kyoto in 1868; at that time Edo was renamed Tokyo. Tokyo Metropolis was formed in 1943 from the merger of the former and the .  - The is a streetcar line in Tokyo, Japan, operated by the Tokyo Metropolitan Bureau of Transportation (Toei). The Arakawa Line is the sole survivor of Tokyo's once-extensive Tokyo Toden streetcar system, but it is not the only tram line in Tokyo, as the privately owned Tokyu Setagaya Line is also classified as a .  - , also known as , is one of two rapid transit systems which make up the Tokyo subway system, the other being Tokyo Metro.  - The or simply Toden, is the tram network of Tokyo, Japan. Of all its former routes, only one, the Toden Arakawa Line, remains in service. The Tokyo Metropolitan Bureau of Transportation operates the Toden. The formal legal name is "Tokyo-to Densha." Its nickname, "Toden," distinguished it from the "Kokuden" (electrified lines of the Japanese National Railways).  - Nishi - Sugamo Station (  Nishi - Sugamo eki ) is a metro station on the Toei Mita Line in Toshima , Tokyo , Japan . On maps , it is marked as an interchange with the Toden Arakawa Line at Shin - Kshinzuka Station .  - , commonly known as Tokyo Metro, is a rapid transit system in Tokyo, Japan. While it is not the only rapid transit system operating in Tokyo, it has the higher ridership among the two operators: in 2014, the Tokyo Metro had an average daily ridership of 6.84 million passengers, while the other system, the Toei Subway, had 2.85 million average daily rides.  - The is a subway line of the Tokyo Metropolitan Bureau of Transportation (Toei) network in Tokyo, Japan. The line runs between Nishi-Takashimadaira in Itabashi and Meguro in Shinagawa. Trains continue with direct service into the Meguro Line of Tokyu Corporation for . The portion between and Meguro is shared with the Tokyo Metro Namboku Line.  - The is a subway line owned and operated by the Tokyo subway operator Tokyo Metro in Tokyo, Japan. Its name literally means "South-North Line". The line runs between Meguro in Shinagawa and Akabane-Iwabuchi in Kita. The Namboku Line was referred to as Line 7 during the planning stages, thus the seldom-used official name is .    Given the paragraphs above, decide what entity has the relation 'part of' with 'toei subway'.
Answer:
nishi-sugamo station