Under myodai (substitutes for Ieyasu) including Masazumi HONDA, Masanari NARUSE and Natsugu ANDO with Fushin Bugyo (Ministrs of Engineering and Construction) including Tadaakira MATSUDAIRA, Tadamasa HONDA and Yasunori HONDA, the reclamation of the outer moat of the castle was rushed by the besieging army and local residents and then the reclamation of Ninomaru was begun in January.
松平忠明、本多忠政、本多康紀を普請奉行とし、家康の名代である本多正純、成瀬正成、安藤直次の下、攻囲軍や地元の住民を動員して突貫工事で外堀を埋めた後に、一月より二の丸も埋め立て始めた。