The Perfect Insider is a great anime because 1) fair play locked room mysteries are fun, 2) the art style reminds me of Inio Asano's work, and 3) it contains an absolutely fantastic entry into the storied canon of Horrible Women™️.

The visuals were made by Baku Hasimoto, who wrote a blog post about how it was made and even released the source code on Github under an MIT license.