gistfile1.js

/*
 * Yet Another Sound-Novel
 * WORK ONLY http://newclassic.jp/archives/4200
 *   Usage: exec in browser console. ex) chrome developer tools
 */

// parse text
var bbtext = function() {
  var i = 0, t = jQuery('.story_main *:not(:has(img,script,noscript,iframe),img,script,noscript,iframe)').text().split('。');
  return function() { return t[i++] + '。'; }
}();

// append background
jQuery('body').append(jQuery('<div id="bb">').attr('style', 'width:100%;height:100%;position:absolute;top:0;left:0;background:black;opacity:0.5;'));
jQuery('body').append(jQuery('<div id="bbt">').attr('style', 'width:94%;color:white;position:absolute;top:5%;left:3%;font-size:110%;font-family:serif;'));

// set event and text
jQuery('#bbt').text(bbtext());
jQuery('#bb,#bbt').on('click', function(e) { jQuery('#bbt').text(bbtext()); });