▁taken ▁back ▁to ▁the ▁ship y ards ▁to ▁have ▁her ▁h ull ▁strength ened . ▁ ▁Oper ational ▁history ▁On ▁completion , ▁O bor o ▁was ▁assigned ▁to ▁Dest roy er ▁Division ▁ 2 0 ▁under ▁the ▁I J N ▁ 2 nd ▁Fle et . ▁During ▁the ▁Second ▁S ino - J apan ese ▁War , ▁from ▁ 1 9 3 7 , ▁O bor o ▁covered ▁landing ▁of ▁Japanese ▁forces ▁in ▁Shang hai ▁and ▁H ang z hou . ▁From ▁ 1 9 4 0 , ▁she ▁was ▁assigned ▁to ▁pat rol ▁and ▁cover ▁land ings ▁of ▁Japanese ▁forces ▁in ▁south ▁China ▁and ▁in ▁the ▁In vas ion ▁of ▁French ▁Ind och ina . ▁ ▁World ▁War ▁II ▁history ▁At ▁the ▁time ▁of ▁the ▁attack ▁on ▁Pear l ▁Har bor , ▁O bor o ▁was ▁assigned ▁to ▁Car rier ▁Division ▁ 5 ▁of ▁the ▁I J N ▁ 1 st ▁Air ▁Fle et , ▁and ▁had ▁deployed ▁from ▁Y ok os uka ▁Naval ▁District ▁to ▁H ah aj ima ▁in ▁the ▁Bon in ▁Islands , ▁from ▁which ▁it ▁subsequently ▁provided ▁cover ▁for ▁Japanese ▁landing ▁operations ▁in ▁the ▁In vas ion ▁of ▁Gu am . ▁ ▁From ▁mid - Dec ember ▁to ▁April ▁ 1 9 4 2 , ▁O bor o ▁was ▁based ▁at ▁K w aj ale in , ▁and ▁from ▁mid - A pril ▁to ▁the ▁end ▁of ▁August ▁ 1 9 4 2 , ▁O bor o ▁was ▁based ▁at ▁Y ok os uka , ▁pat rolling ▁in