The “boundary” is not just a metaphor. In this setting, it is a literal, liminal space: a crumbling cathedral at the edge of a forgotten city, a mirror realm between dreams and waking, or a forbidden ritual ground where wishes come true at the cost of one’s humanity.
The anime also explores the complexities of human relationships, showcasing the intricate web of connections between characters. Shiki and Katsuragi's partnership is a prime example, as they navigate their differences and learn to trust each other. The series also delves into the consequences of toxic relationships, highlighting the destructive nature of manipulation and abuse. Haitoku no Kyoukai