Today, Paradox Interactive released a trailer for an expansion to Europa Universalis IV, titled Mandate of Heaven.
Trailer: https://www.youtube.com/watch?v=6ijdgWnd2Yo
In it, a Chinese woman and a Japanese woman give short, paralleled speeches about claiming the Mandate of Heaven.
Even if the Mandate of Heaven wasn't something that was constantly on everybody's mind like video games might lead us to believe (as I read in /u/tiako's answer to this question), I can believe that a Chinese faction planning to rebel would cite the Mandate of Heaven as part of their justification. I have a harder time believing the same thing of, say, an Ikko-ikki sect, or of any of the daimyo rebelling against the Shogun. Am I wrong to think the Japan part of that trailer is ahistorical? And did any of the ruling classes of any Chinese tributaries cite the Mandate of Heaven to legitimize their own dynasties?
It's kind of misleading, yes (although I'm low-key ecstatic to see Paradox give East Asia some love), as the 'Mandate of Heaven' isn't really a paramount thing in either China or in Japan. Instead of being an actual policy legitimizing rebellion against the emperor, it has historically been more used as PR for the victorious rebels to justify their new dynasty. It's somewhat equivalent to the concept in the West that the "winner writes the history books"; but, as the idea of 'Heaven giving the people a blank check to rebel against an evil tyrant' is very romantic, has now become cliche.
Since the Heian period of Japan was heavily influenced by the Tang Dynasty during the 800s, it's actually interesting to see how different the Japanese politico-religious systems were. While both were kinda similar in their usage of a "demigod" cult of personality surrounding the emperor, the Japanese emperors were both more and less restricted than their counterparts across the sea. While, successful rebellions on the Continent were justified by rebels with favorable superstitions and portents, the Japanese claimed to be direct descendants of Heaven and, thus, could not be stripped of the right to rule for any reason whatsoever. Pretty smart to have cherry-picked that, huh?
Of course, saying that one is the descendant of Heaven doesn't necessarily mean that you'll automatically be listened to. As I'm sure you know, Japan emperors (even during the Taisho and militarist periods leading up to WW2) have rarely wielded much power, instead serving as motivational figureheads who delegated power to the regional (and later, bureaucratic) players behind the scenes.
So, in summary, you're pretty spot on. The 'Mandate of Heaven' isn't really some heavenly blank check to rebel (East Asian philosophies generally aren't as focused on deities and creation myths) in either Japanese or Chinese bureaucracies. It's merely a move used by Sinocentric cultures (that includes much of Southeast Asia) to justify regime changes more realistically caused by real-life political or economic conflicts.
There's not really any one book that covers this stuff (as the 'Mandate of Heaven' really isn't that paramount in reality), but the book The Japanese Experience: A Short History of Japan by William Beasley includes a short, succint section on the Japanese incorporation of Tang ruling styles during the Asuka period.