ak uf u ▁could ▁ensure ▁none ▁would ▁become ▁powerful ▁enough ▁to ▁challenge ▁the ▁b ak uf u ' s ▁supre m acy . ▁This ▁is ▁consistent ▁with ▁the ▁generally ▁agreed ▁r ationale ▁for ▁the ▁Tok ug awa ▁b ak uf u ' s ▁implementation ▁of ▁the ▁system ▁of ▁alternate ▁attend ance , ▁or ▁s ank in - k ō ta i . ▁ ▁Direct ing ▁trade ▁pre domin antly ▁through ▁Nag as aki , ▁which ▁came ▁under ▁Toy ot omi ▁H ide y oshi ' s ▁control ▁in ▁ 1 5 8 7 , ▁would ▁enable ▁the ▁b ak uf u , ▁through ▁tax es ▁and ▁lev ies , ▁to ▁bol ster ▁its ▁own ▁tre as ury . ▁This ▁was ▁no ▁small ▁matter , ▁as ▁lack ▁of ▁wealth ▁had ▁limited ▁both ▁the ▁preceding ▁Kam ak ura ▁b ak uf u ▁and ▁the ▁Mur om achi ▁b ak uf u ▁in ▁cru cial ▁ways . ▁The ▁focus ▁on ▁the ▁removal ▁of ▁Western ▁and ▁Christian ▁influence ▁from ▁the ▁Japanese ▁arch ip el ago ▁as ▁the ▁main ▁driver ▁of ▁the ▁ka ik in ▁could ▁be ▁argued ▁to ▁be ▁a ▁somewhat ▁euro cent ric ▁reading ▁of ▁Japanese ▁history , ▁although ▁it ▁is ▁a ▁common ▁per ception . ▁ ▁Nevertheless , ▁Christian ity ▁and ▁the ▁two ▁colonial ▁powers ▁it ▁was ▁most ▁strongly ▁associated ▁with ▁were ▁seen ▁as ▁genu ine ▁thre ats ▁by ▁the ▁Tok ug awa ▁b ak uf u . ▁Once ▁the ▁rem n ants ▁of ▁the ▁Toy ot omi ▁cl an ▁had ▁been ▁defeated ▁in ▁