Some websites not displaying japanese correct

Hello people,

so I can surf lots of sites in japanese, and all symbols are shown correctly. But there are also some sites where the symbols are not shown correctly.
Compare "只今リニューアル中" (Oh I hope it'll display properly here :p) for example, with "B`ƒnƒKƒNƒŒ`)ƒZƒb".
 Could someone please explain this, and tell me if I could solve this somehow . Thanks

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