Why it worked
The video taps into the popular "isekai" trope and the massive fanbase of Jujutsu Kaisen, presenting an interactive "choose your own adventure" style experience that appeals to fans' desire to immerse themselves in their favorite anime worlds.
Summary
The video presents a hypothetical scenario of being isekai'd into the world of Jujutsu Kaisen, where the user can choose their own story and interact with characters who remember their actions. It then reveals this concept is realized through a downloadable app called OOC, "The Playable Anime."