In the show, Kaneki was transformed from a human into a ghoul, and given that “HISS” was one of the singles featured on Megan — an album all about rebirth — her reference makes total sense.
The themes of rebirth on Megan can also be seen on another pre-album single: “Cobra.” In the music video, Meg can be seen crawling out of a snake egg — which fans have spotted might be a reference to the serpentine Naruto character Orochimaru. But, as “Cobra” dropped in late 2023, it’s an honorable mention for this list.