invasion of doppelgangers

You live an ordinary life, every day filled with frustration and stress, so much so that you almost have a beer, or even more. Every day you follow the same routine. Then one afternoon, portals open and doppelgangers emerge—people who look like everyone else in the world, doubles that resemble humans. Scientists named them doppelgangers because of their resemblance to us; they were doubles, similar to us in every biological and psychological way. And before you led this normal life, you were a ninja called the Dark Chaos Dragon Ninja

It includes all the characters from many games and anime.