Both dramas are pretty dark mystery-thrillers with sci-fi elements. In both dramas, people die in weird circumstances.
Pandora's Box (2021)
Related
Simmilar theme, same vibe, not many episodes, great acting, not much censorship and weird scientific mackgroud and explanations.
both have a strange way of conveying the story. both about consciousness and how easily it can be influenced by others
Both dramas are set in Japan (even if Pandora's Box is a cdrama).
Both dramas are short and weird. With Pandora's Box, the weirdness comes from the sci-fi elements and the plot. With Yamaneko, the weirdness mostly comes from the characters.
Both dramas have a similar kind of surprise villain.
These dramas are very different in many ways, but I did think of Yamaneko a few times while I was watching Pandora's Box.