Himitsu The Top Secret (2016)

In both the scientists have discovered a way to read the memories of the deceased and use it to solve a mystery by linking their brain to that of even a criminal. In both the procedure has negative side effects and can be done only using someone with a strong mind. Both brought up the problem of the unreliability of humans' memories, since we can distort the facts. In both the protagonist has hallucinations.

Both are fucked up and quite graphic. Both also deals with the loss of a friend and the cause itself.