ized ▁formation , ▁known ▁as ▁the ▁Nak ai ▁Det achment , ▁which ▁had ▁been ▁det ached ▁from ▁the ▁ 2 0 th ▁Division ▁during ▁the ▁Fin ister re ▁Range ▁campaign . ▁He ▁was ▁later ▁placed ▁in ▁command ▁on ▁the ▁I J A ▁ 2 0 th ▁Division . ▁ ▁Biography ▁Nak ai ▁was ▁born ▁in ▁T ott ori ▁Pref ect ure . ▁He ▁graduated ▁from ▁the ▁ 2 9 th ▁class ▁of ▁the ▁Imperial ▁Japanese ▁Army ▁Academy ▁in ▁May ▁ 1 9 1 7 ▁and ▁from ▁the ▁ 4 2 nd ▁class ▁of ▁the ▁Army ▁Staff ▁College ▁in ▁November ▁ 1 9 3 0 . ▁As ▁a ▁junior ▁officer , ▁he ▁participated ▁in ▁the ▁Si ber ian ▁Ex ped ition . ▁In ▁the ▁ 1 9 3 0 s , ▁he ▁had ▁extensive ▁experience ▁in ▁China , ▁where ▁he ▁served ▁as ▁a ▁military ▁attach é ▁from ▁ 1 9 3 7 . ▁In ▁May ▁ 1 9 3 9 , ▁he ▁was ▁promoted ▁to ▁colon el ▁and ▁in ▁September ▁of ▁the ▁same ▁year ▁was ▁assigned ▁to ▁the ▁China ▁Ex ped ition ary ▁Army ▁on ▁the ▁front ▁lines ▁of ▁combat ▁in ▁central ▁China ▁in ▁the ▁Second ▁S ino - J apan ese ▁War . ▁From ▁ 1 9 3 9 – 1 9 4 0 , ▁he ▁served ▁on ▁the ▁senior ▁staff ▁of ▁the ▁I J A ▁ 2 1 st ▁Army ▁task ed ▁with ▁the ▁C anton ▁Operation , ▁and ▁from ▁February ▁ 1 9 4 0 , ▁on ▁the ▁senior ▁staff ▁of