Widely observed, never acknowledged, and filed LOW for exactly that reason. The parallels are specific: a device that lets one person enter another's dream, a corridor that becomes the wrong way up, a mirror opened as a door between states, and a character falling to wake. Against it: Nolan has said he wrote Inception over roughly ten years and has named architecture, heist films and his own Following as sources, not Kon. Satoshi Kon died in 2010 and made no claim.