User blog comment:Dragonjet/DMM Cookies: August 2015/@comment-26154973-20150805212514

It seems like restricted pages want ckcy=1 AND absence of cklg, so in Chrome I was able to fix navigation with

var expDate = Math.round(new Date("2019/01/01 00:00:00").getTime / 1000);

chrome.cookies.set({   url: "http://www.dmm.com/", domain: ".dmm.com", path: "/", name: "cklg", value: "ja", expirationDate: expDate });

chrome.cookies.set({   url: "http://www.dmm.com/", domain: ".dmm.com", path: "/netgame/", name: "ckcy", value: "1", expirationDate: expDate });

chrome.cookies.set({   url: "http://www.dmm.com/", domain: ".dmm.com", path: "/netgame_s/", name: "ckcy", value: "1", expirationDate: expDate });

chrome.webRequest.onBeforeSendHeaders.addListener(   function(details) {        for (var header of details.requestHeaders) {            if (header.name === "Cookie") {                header.value = header.value.replace(/;\s*cklg\s*=ja\s*/, "");                break;            }        }        return {requestHeaders: details.requestHeaders};    },    {urls: [        "http://www.dmm.com/netgame_s/*",        "http://www.dmm.com/netgame/social/application/*"    ]},    ["blocking", "requestHeaders"] );