Residential addressing comes to Shiomi
In January 1988 (Shōwa 63), the residential address system was introduced in the Shiomi district, twenty years after the land joined the ward.
"Kōtō-ku no Ayumi" records "the residential address system introduced in the Shiomi district" in January Shōwa 63. Wikipedia's list of town names in Kōtō-ku gives 1 January 1988 both for the creation of the town areas of Shiomi 1-chōme and 2-chōme and for the introduction of residential addresses, and gives the earlier name as "Shiomi 1 and 2 (whole)". This day has not yet been confirmed from a ward public notice.
Neighbouring Shiohama, Tatsumi and other districts received residential addresses on 1 April 1968, so Shiomi came twenty years later. In the meantime, addresses probably used land-lot numbers (地番).
Sources
Confirmed in primary or official sources