It's theorized that Toyosatomimi no Miko and Saki Kurokoma are Prince Shoutoku and the prince's trusty steed, the Kurokoma of Kai. In the outside world, there is a legend about how they were led by Prince Shoutoku's retainer, Choushimaru, back and forth between the Ikaruga and Oharida palaces along a route that would later be called the Taishi's Paths. If only Choushimaru was still around to shed light on the matter...!

The Animal Realm is one of the Six Realms that make up the universe in Buddhist cosmology. The Six Realms are Heaven, the Human Realm, Hell, the Asura Realm, the Animal Realm, and the Preta Realm. Traveling between the Animal Realm and Gensokyo is supposed to require permission from the Yama... However, there appear to be secret paths between them that the Yama is unable to or too busy to regulate. The Animal Realm is mostly inhabited by animal spirits like Saki Kurokoma, but some humans live there too. This could be because humans can be considered to be a type of animal, though it's also possible that they are the souls of humans sent there to wait until they reincarnate into animals.

Mibube is the name of the team of specialists that supported Prince Shoutoku in the prince's official duties. It started out as an official organization tasked with tutoring princes and princesses, and it was supposed to disband when their pupils no longer required their services. However, power gained is not so easily relinquished, and many members of the Mibube ended up taking additional roles in the imperial court. The first instance of the formation of a Mibube was for the tutelage of Prince Shoutoku. They managed every facet of the prince's life and beyond, going so far as to oversee the construction of the prince's tomb. The leader of the Mibube was Hata no Kawakatsu.

In the past, an incident occurred where people were duped into worshipping a new god called Tokoyo no Kami. The architect of this incident was Ooube no Oo, and it was resolved by Hata no Kawakatsu. It is believed that Tokoyo no Kami was a deified swallowtail butterfly caterpillar. This could've been purposefully designed to offend the Hata clan, who were in charge of the silkworm industry, and Kawakatsu specifically since there was famously a mandarin tree in Kawakatsu's garden. (Swallowtail butterfly caterpillars eat the leaves of mandarin trees.) Furthermore, it's speculated that Hata no Kawakatsu was forced to resolve this issue because Ooube no Oo was a member of the Mibube. Tokoyo can be written in two ways: one meaning "eternity" and the other "eternal night." This implies that this new faith might have preached a return to the old ways of life, where people formed hunter-gatherer societies and worshipped the Moon. This would have been in direct opposition to the predominant ideology of the time, where people worshipped the Sun and led a lifestyle centered around agriculture. Perhaps these people thought the hunter-gatherer lifestyle, where you hunt for prey cloaked in the darkness of night and sleep during the day, was an easier and more natural way to live. Even today, there are still some people who share that sentiment. The Hata clan is credited with spreading knowledge of rice cultivation throughout Japan, so again, it seems like Ooube no Oo was trying to antagonize them. It is also theorized that this Tokoyo no Kami faith evolved from Taoist teachings.

"Over there, you can see one of the shops I run." "Oh, is that right?" "Yeah, and over there are some shops run by these guys called Kicchou and Toutetsu." "Wow, you've really made a name for yourself here, haven't you?" "Hehehe." "Hey, let's have a race for old time's sake. The first one to that shop over there wins!" "Haha, are you sure you wanna challenge me? I was the great Umayado no Miko's jet-black pegasus!"