JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://wp-simplicity.com/wp-content/themes/simplicity-child-simplicity/style.css">
<div class="article">
     <h1 class="entry-title">投稿ページ タイトルを 指定した 場所で改行したい</h1>

    <p class="post-meta"> <span class="post-date"><span class="fa fa-clock-o fa-fw"></span><span class="entry-date date published"></span></span> <span class="post-update"><span class="fa fa-history fa-fw"></span>
        <time class="entry-date date updated" datetime="">2015/11/25</time>
        </span>
    </p>

JavaScript

(function ($) {
    $(function () {
        var ptn = / /g,
            replace = '<br>',
            title = $(".entry-title").text().replace(ptn, replace);
        $(".entry-title").html(title);
    });
})(jQuery);