One 15000-series trainset on the Tozai Line is currently operating as the "Sonic the Hedgehog" train. Six different versions of Sonic, representing each era, are featured on the car sides. The train is scheduled to run through Wednesday, November 4, 2026. Timetables and operating sections vary by day.

Using the "Tokyo Metro my!" app, visit four locations: PARCO FACTORY IKEBUKURO at Ikebukuro PARCO, SEGA STORE TOKYO at Shibuya PARCO, the Subway Museum, and KUA`AINA Tokyo Skytree Town Solamachi. The event runs through Sunday, November 1, and participation is free. Transportation, communication charges, and admission fees are borne by participants.

Collect all four stamps to receive a completion paper craft, and enter a lottery for a commemorative stainless-steel bottle. Quantities and number of winners are limited.

A set including a Tokyo Metro Original 24-hour Ticket (adult) with a Sonic 35th anniversary design and a dedicated mount is on sale for 700 yen (tax included). Sales run through Monday, November 30, limited to 5,000 sets. Available at select Animate stores in Tokyo, Saitama, Chiba, and Kanagawa; ends when sold out.