Explanation
You can specify displayed quotes before and after <blockquote> tags. Specify your desired quotes using "quotes".
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="content-type" content="text/html;charset=shift_jis">
<title>Sample</title>
<style type="text/css"><!--
blockquote { quotes:"【" "】" }
blockquote:before { content:open-quote }
blockquote:after { content:close-quote }
--></style>
</head>
<body>
<h1>Sample</h1>
<p>
Quote from one phrase japanese people knows<br>
<blockquote>
春はあけぼの。缶詰もあけぼの。昔の漫画はぼのぼの。縁側でほのぼの。
</blockquote>
</p>
</body>
</html>