sentences:  After the abolition of the han system in the first wave of prefectural mergers in 1871/72, several surrounding areas (parts of Urawa, Kosuge, Shinagawa and Hikone prefectures) were merged into Tokyo, and under the system of (numbered) "large districts and small districts" "(daiku-shōku)", it was subdivided into eleven large districts further subdivided into 103 small districts, six of the large districts (97 small districts) covered the former city area of Edo.When the ancient ritsuryō districts were reactivated as administrative units in 1878, Tokyo was subdivided into 15 [urban] districts "(-ku)" and initially six [rural] districts ("-gun"; nine after the Tama transfer from Kanagawa in 1893, eight after the merger of East Tama and South Toshima into Toyotama in 1896).Both urban and rural districts, like everywhere in the country, were further subdivided into urban units/towns/neighbourhoods "(-chō/-machi)" and rural units/villages "(-mura/-son)".