The extension to was completed in September 1997, and the last stretch from Tameike-Sanno to Meguro was completed on September 26, 2000, when through service to the Tokyu Meguro Line started. Through service with the Saitama Rapid Railway Line commenced when it opened in March 2001 and accommodated traffic to and from Saitama Stadium during the 2002 World Cup. Although the Saitama Line is more or less a northern extension of the Namboku Line, it nevertheless remains a private entity to which the Namboku Line offers through services with.