“I thought you were expressionless, but your personality is changing a mile a minute.” – Marisa
Hata no Kokoro is a menreiki youkai, an amalgamation of masks used in a certain performance art called Gigaku. The art in question has long since ceased existing in practice, but as we all know, it’s when things are forgotten in the real world that they have a habit of popping up in Gensokyo.
The menreiki are a subclass of tsukumogami, which are the supernatural extensions of tools or objects occupied by one of the countless Shinto deities. We’ve encountered one such tsukumogami in the past, the umbrella youkai Kogasa Tatara, and several other youkai within this category feature in the 14th main Touhou game: Double Dealing Character.