A nice graphic depicting the process of land readjustment (土地区画整理事業), which is defined by the Japanese land readjustment law (土地区画整理法). From a slide deck on TOKYU’s Transit-Oriented Development:
Similar graphic from 国土交通省, the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), Urban Development and Improvement Division 市街地整備課 (source):
And an example from Urban Renaissance (UR), the semi-public housing authority (source):
As seen in these example, land readjustment results in more standardized parcels of land.
See also:
the tokyo files: urban design 東京の都市デザイン 