Tengen Toppa Gurren Lagann opens on the bridge of a vast space battleship as we see its mature and scarred commander, who holds in his hand a small conical key, launch an attack to open the final battle of an intergalactic war.
The anime version of Higurashi: When They Cry does this with several of its' arcs, particularly Onikakushi-hen and Watanagashi-hen, which kick things off with the murder of one or more major characters and then hit the 'rewind' button back to the chronological start of the arc.
Occultic Nine's first episode starts with the discovery of hundreds of corpses found dead in a lake, with the story going back one week showing the events leading up to it.
BUNNI HOW WE FIRST MET TV TROPES CODE
Code Geass almost did this, according to Word of God the show's creators briefly considered beginning the series by showing Lelouch and Suzaku pointing guns at each other, as per Episode 25 as the first scene, then going back several months to show how the two friends have gotten into such a situation.
He then meets Kenshin and challenges him to a duel, after Kenshin is forced to accept the challenge does Kenshin return and tell his friends why his brother-in-law wants revenge. The Big Bad of the arc Enishi, has destroyed two buildings from people who have met Kenshin (one only once).
The Rurouni Kenshin manga has a variation.
In flashbacks, Roger shows how this came to pass.
The Big O, episode 7, opens with Angel and Roger trapped in an old office building on the bottom of the ocean.
The anime Berserk (1997) follows the same progression by showing the Black Swordsman Arc in episode 1, and spending the rest of its 25 episodes on the Golden Age Arc. Then the Golden Age Arc (volumes 3 to 14) goes back in time and shows us the epic tragedy of how the brotherhood they forged on the battlefield was torn apart by Griffith's betrayal, with Griffith ascending to demonhood and Guts becoming He Who Fights Monsters. At the end of the Black Swordsman Arc we learn that the God Hand includes Guts' Arch-Nemesis Griffith, who used to be Guts' friend. At this point Guts is missing his right eye and left hand, and carries the cursed Brand of Sacrifice on his neck, which every night summons evil spirits to devour him.
Berserk opens with the Black Swordsman Arc (volumes 1-3), introducing main character Guts as a vicious Nominal Hero on a Roaring Rampage of Revenge against the five evil deities called the God Hand, as well as their monstrous servants, the Apostles.
I, as if drunk on a cocktail mixed with anxiety and uncertainty, call upon my memory in a haze.