Long before it became the first stop on the south-bound shinkansen from Tokyo Station (and, for many of the city's foreign residents, a key juncture on the dreaded schlep to the immigration office), Shinagawa was known as the first rest stop along the Tokaido Highway from Edo to Kyoto.
Started in 1990, this annual festival tries to educate the younger generation in the area's history. It features taiko drumming and parades of people in traditional costumes alongside the less era-specific flea markets and marching bands. There's even a fire-walking rite by monks at Honsenji Temple (September 29 1pm). While the oiran dochu (courtesan procession) takes place on Saturday afternoon from 4pm to 7.30pm, most of the action is centred on Sunday.
For more details, check the event's Facebook page.