Isekai is the big trend in anime right now, and we're just sort of dealing with it. Those in the know may have hissed just reading the word, but let's explain for those who still only watch a healthy amount of anime. Isekai (roughly translating to "different world") is a subgenre in which a normal Earth person finds themselves transported to another world. Many popular works star an underachieving human who ends up in a video game-style fantasy world, surrounded by gorgeous women. Think shows like Re:Zero, KonoSuba, or Rising of the Shield Hero.
But what if we told you that, years ago, Sonic the Hedgehog paved the Isekai road? Well that's exactly what happened in Sonic X.
Any Sonic fan worth their red shoes will remember Sonic X, the early 2000s anime that became part of the infamous 4Kids block in the West. The plot follows the blue blur and friends as they fight the usual battle against Dr. Eggman, only to accidentally activate an explosion of Chaos Emerald energy. This teleports them to a parallel world dominated by humans instead of talking animals. So yes, Sonic X is an Isekai and that makes Sonic an Isekai hero.
That said, Sonic X does technically represent a subset of Isekai called "Reverse Isekai." This fact was pointed out in a discussion on the r/anime subreddit. Isekai proper is defined by an Earth resident traveling to another world. As Sonic does the opposite in Sonic X, it represents Reverse Isekai.
The same logic might hold true for the Sonic the Hedgehog live-action movie. Sonic travels through a ring portal to Earth, where he befriends and eventually saves the locals. Then again, Sonic suggests that he's just from another planet, not another dimension entirely. This would make movie Sonic an alien and not an Isekai protagonist.
What does this all mean in the end? Nothing, really. Even though Sonic X does predate the current Isekai invasion, it's far from the first. InuYasha is a famous example from years before. Outside of anime, the storytelling device of otherworld travel is present in classic stories like Alice in Wonderland and The Chronicles of Narnia.
Still, it's fun to think that Sonic ranks among the various NEETs who get whisked away to a waifu paradise. Only in his version, he was still stuck with Amy and hung out with a twelve-year-old boy. Honestly, we're not sure if we'd have rather seen Sonic flanked by attractive women. Sonic 06 showed us where that road leads. We'll stick with Sally Acorn, thanks.