ior ated ▁for ▁Japan , ▁in ▁March ▁ 1 9 4 4 , ▁the ▁I J A ▁ 9 th ▁Arm ored ▁Regiment ▁of ▁the ▁ 1 st ▁T ank ▁Division ▁was ▁re ass igned ▁to ▁the ▁I J A ▁ 3 1 st ▁Army , ▁and ▁sent ▁to ▁Sa ip an , ▁where ▁it ▁was ▁anni h il ated ▁at ▁the ▁subsequent ▁Battle ▁of ▁Sa ip an ▁and ▁Battle ▁of ▁Gu am . ▁The ▁remaining ▁three ▁reg iments ▁participated ▁in ▁Operation ▁I chi - Go ▁in ▁main land ▁China . ▁The ▁I J A ▁ 3 rd ▁Arm ored ▁Regiment ▁of ▁the ▁ 1 st ▁T ank ▁Division ▁was ▁re ass igned ▁to ▁China ▁and ▁attached ▁to ▁the ▁ 1 1 th ▁Army ▁until ▁the ▁end ▁of ▁the ▁war . ▁ ▁In ▁March ▁ 1 9 4 5 , ▁the ▁ 1 st ▁T ank ▁Division ▁with ▁its ▁ 5 th ▁Arm ored ▁Regiment ▁was ▁re ass igned ▁to ▁the ▁Japanese ▁home ▁islands ▁in ▁prepar ation ▁for ▁the ▁expected ▁invasion ▁by ▁Al lied ▁forces . ▁It ▁gained ▁the ▁I J A ▁ 1 st ▁Arm ored ▁Regiment ▁from ▁the ▁ 3 rd ▁T ank ▁Division , ▁and ▁formed ▁part ▁of ▁the ▁I J A ▁ 3 6 th ▁Army ▁under ▁the ▁Japanese ▁Tw elf th ▁Area ▁Army . ▁The ▁headquarters ▁unit ▁and ▁I J A ▁ 1 st ▁Arm ored ▁Regiment ▁were ▁based ▁in ▁S ano , ▁To ch igi , ▁with ▁the ▁I J A ▁ 5 th ▁Arm ored ▁Regiment