Light Yagami Cameo
Last Updated: 4/9/2017
This easter egg is found in Episode 11 titled, "Memento Mori".
When Mayu is given the choice to send either Harada (her idol) or a complete stranger she’s never met to the Void, we can see the other person she has to choose from is actually Light Yagami from Death Note.
Lights appearance in Quindecim makes sense for two reasons:
1) Both Death Note and Death Parade were produced by the same company, Madhouse. This means that both shows are more likely to take place in the same universe.
2) Those who remember the rules of Death Note will recall that since Light used the death note his soul is doomed to remain in purgatory (aka Quindecim) for eternity, as humans who use the death note can neither go to Heaven nor Hell.
This will explain why Light is seen in a completely different room rather than hanging around Ginti’s bar.