Hanimon

Hanimon is based on japanese clay dolls, Haniwa. While Haniwa covers all terracotta clay dolls used in rituals & burials, they are most commonly associated with the three hole face and up/down arm pose. Integrating these types of Haniwa in pop culture started becoming popular in the 90s. Among other modern depictions, Gyroids from Animal Crossing, which are also called Haniwa in japanese, are probably most well-known.

Kokeshimon

Kokeshimon is based on japanese wooden Kokeshi dolls! It especially resembles the modern style versions, which commonly feature a black bob, some form of red hair piece, usually a bow, and a pretty kimono, often adorned with flower patterns.

Karakurumon

Karakurumon is based on japanese Karakuri dolls. "karakuru" means 'pulling on strings', and the noun "karakuri" has come to mean 'mechanism' or 'trick'. These dolls had automated mechanisms performing some sort of movement. Karakurumon especially resembles the tea serving robot.

Kaguyamon

Kaguyamon is based on princess Kaguya from japanese mythology.

Originating from the Tale of the Bamboo cutter, Kaguya-hime was found inside of bamboo, and came from the moon. By the end of the story she returns to the palace on the moon.

Kaguya has ben referenced in modern media many times. Due to her connection with the moon, the lunar orbitor SELENE was also known as Kaguya. The Pokémon Celesteela, based on Kaguya too, also takes on a space theme.