Shinto

The concept of a post death judgement is one which is shared by a great many religions to a greater or lesser extent.

For the ancient Egyptians, post death judgement was central to their religion.

According to the Christian bible, humans will ressurected and they all be judged at the same time, some going to heaven some going to hell.

In The Book of Revalations, in the New Testament of the Christian Bible, the process of judgement is described as follows.

And I saw the dead, great and small, standing before the throne, and books were opened. Another book was opened, which is the book of life. The dead were judged according to what they had done as recorded in the books. Revelation 20:12 (p. 921)

Hence, according to this Christian rendition of judgement, the dead are judged by what is written in the book of life. Sometimes we hear that Saint Michael looks to see whether our name is written in the book, but Revelations is quite clear that it is not our name but what we have done that is written.

The concept of judgment is not as strong in Japan as it is in the West, but there exists a "Buddhist" tradition that the judgement of the dead is performed by "Enma-sama" (Mister Enma) or "Enma-Ou" (King Enma). Enma is a god that is inherited from an Indian god, via China, with Daoist influences. Enma also has a prominent place in the Tibet Buddhist "book of the dead." Enma is the most famoust of the ten kings or Buddhist gods that are worshipped in Japan and is believed to be an avatar of Jizou Boddhistatva. Enma stands at the entrance to hell (rather than heaven) and decides which of the 6 paths a dead person will take. Some people go to straight to hell, some are born again starving, some are born again as an animal, some are born into the world of war, some are born again as a human, and some are born again in heaven.
Enma holds a wooden staff staped like a ruler, such as held by the judges of the Sumo ring. He also has a book, but he usually seems to have a pen so that the write the verdict in the book rather than read from it. According to popular tradition in Japan, the first thing that Enma does to the dead when they arrive at his court is tear their tongue out, presumably so they cannot complain or speak out against his verdict. Enma reaches his verdict by looking in the "Jouhari" Kagami in which he can see the dead person's life, particularly any of the nasty things that the dead person has done. Accordng to some he also has a "Enma-register" in which the dead person's ill deeds are written. In an Edo period picture drawn by a Buddhist priest trying to discourage women from killing their children, Enma is shown looking into the mirror to see a younger version of the dead person before him, suffocating a child with a pillow.

There are many similarities and differences between these traditions. In both those that are deemed free of sin fare better than those that are judged to be guilty. The latter go to some sort of hell which often depicts humans being torn part and or roasted. In Christianity judgement takes places at the same time - at "Judgement Day." In Japan, on an individual basis. In Christianity the judgement takes place at the gates of heaven or by good, or someone heavenly, in Japan it takes places at the gates of hell by someone much more fearful: the god of the dead. The difference that I would like to draw attention to is that in both cases we are judged based upon a record of our lives. In Christianity our lives are written in a book. In Japan, lives are recorded as images in a book too but more importantly, as we stand mute before a mirror.