The Grandpa Videos™ are enigmatic recordings of a disputed nature in the possession of one "old fart." Though there are many theories as to what is depicted on the elusive Grandpa Videos™, the contents remain a mystery under the watchful eyes of their keeper. There is no telling what defines a typical Grandpa Video™; perhaps they are a telling of a dark past, or a prophecy of a dark future.
As of the events of Zero Escape: Virtue's Last Reward, the Grandpa Videos™ are known to be held by one Tenmyouji, and potentially coveted by Quark.