15 July 1972 - Sazanami service starts coinciding with opening of the underground Sōbu Line platforms at Tokyo Station.
16 March 1991 - Sazanami service are rerouted via the Keiyō Line from Tokyo.
2 July 1993 - 255 series EMUs are introduced on View Sazanami services from Tokyo to Chikura.
16 October 2004 - E257-500 series EMUs are introduced.
10 December 2005 - The View Sazanami name is discontinued, and all services are made entirely no-smoking.
The opening of the Tokyo Bay Aqua-Line road across the Tokyo Bay in 1997 saw increased competition from long-distance bus services offering cheaper fares, resulting in decreasing ridership figures on the Sazanami services. From the start of the 15 March 2014 timetable revision, the number of services was reduced to six return workings daily.