Guardian Shield (ガーディアンシールド, Gādian Shīrudo), also known as Keeper Command K03 (キーパーコマンドK03, Kipā Komando Kē Zero Surī), is a Keshin punching catch hissatsu technique introduced in Inazuma Eleven GO.
The user closes their eyes and spreads both of their arms to the sides, quickly getting into position and opening their eyes again, crossing their arms in an X-shape and tinging the surrounding area in indigo energy. As they spring into the air and reel back both of their arms, they clench both of their hands into fists with their Keshin appearing behind them, covering the field with a white mist. They then punch both of their fists together, with their Keshin following suit and joining its shield parts into one, creating a green barrier in front of them, rapidly deflecting the ball and coming back into reality if successful.
The strength of this hissatsu technique in Inazuma Eleven GO was listed as "C" in "Inazuma Eleven GO Shine/Dark: Nekketsu Official Guidebook Kyuukyoku-ban".
In the Inazuma Eleven anime series, it is one of the hissatsu techniques which has never been successfully used.
In Inazuma Eleven GO Strikers 2013, fully voiced lines from game files indicate it was planned to have been in the game, but, ultimately, ended up being unused.
In Inazuma Eleven GO, despite Keshin hissatsu descriptions not being readable in normal gameplay, its description from Inazuma Eleven Strikers 2012 Xtreme can be found in the game's files.
In the European versions, a translated version of this description can be found (EN: Take the direct approach to goal defence and use a massive shield!).