▁lowest ▁win - loss ▁ratio ▁of ▁any ▁post - war ▁y ok oz una . ▁ ▁After ▁ret irement ▁Upon ▁ret irement ▁M ien ou mi ▁took ▁the ▁name ▁of ▁Mus ash ig awa ▁O y ak ata ▁ ▁and ▁established ▁Mus ash ig awa ▁stable ▁in ▁ 1 9 8 1 . ▁Until ▁then ▁D ew an ou mi ▁stable ▁had ▁disc ou rag ed ▁any ▁breaking ▁away , ▁and ▁he ▁was ▁the ▁first ▁from ▁D ew an ou mi ▁in ▁ 6 2 ▁years ▁to ▁am ic ably ▁set ▁up ▁a ▁new ▁stable . ▁By ▁ 2 0 0 0 ▁Mus ash ig awa ▁stable ▁had ▁become ▁one ▁of ▁the ▁strong est ▁st ables ▁in ▁sum o ▁with ▁a ▁y ok oz una , ▁Mus ash im aru , ▁and ▁three ▁ ō ze ki , ▁De j ima , ▁Mus ō y ama ▁and ▁Mi y abi y ama . ▁Mus ash ig awa ▁ ▁performed ▁an ▁early ▁kan re ki ▁do hy ō - iri ▁in ▁ 2 0 0 7 ▁( norm ally ▁performed ▁on ▁a ▁y ok oz una ''' s ▁ 6 0 th ▁birth day ) ▁to ▁mark ▁the ▁ 2 5 th ▁anni versary ▁of ▁the ▁found ing ▁of ▁Mus ash ig awa ▁stable . ▁On ▁September ▁ 8 , ▁ 2 0 0 8 , ▁he ▁became ▁the ▁chairman ▁of ▁the ▁Japan ▁Sum o ▁Association ▁following ▁the ▁res ignation ▁of ▁K itan ou mi . ▁One ▁of ▁his ▁first ▁actions ▁was ▁to ▁demand