Not only was the protagonist breaking the fourth wall, but the author also was directly contributing through notes outside of the panel boundaries. This series does meta jokes really well.
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[DISC] RTA Sousha wa Game Sekai kara Kaerenai - Chapter 14.4 [BONUS] | Spyke
I like that he's still breaking their 4th wall minds in this bonus chapters.
Not only was the protagonist breaking the fourth wall, but the author also was directly contributing through notes outside of the panel boundaries. This series does meta jokes really well.