How can we get website cache data with some special method?

I have a problem that is we can see a website load a lot of data when browser accessed, such as mouseover popup data, but we cannot find that data in html source code or any cache data or local storage about that in chrome and I am quit sure that is not real-time data since that I tried turn off the network, it also can be pop-up. So my question is that where is the data store? How can we find that and access it?