|This article is about a/an conditiion in Choushinsei Flashman.|
The Anti-Flash Phenomenon is a condition which affects natives of the Flash System after spending a certain amount of time away from the system, forcing them to return or else they would die. Hero Titan sucumbed to the Anti-Flash Phenomenon and the Flashmen were forced to leave Earth within a year lest they suffer the same fate.
The nature of the Phenomenon is eventually revealed near the end of the series: Earth's environment will become toxic to the Flashmen over time; the warmth of the sun burns like fire, water irritates the throat to the point of choking them, as does the scent of flowers; touching another human gives off an electrical shock. With a short time remaining before these effects reach fatal levels, the Flashmen must finish the battle quickly and return to the Flash System.