Just finished the first part of Chapter One of Celestial Realms. Considering that the Moto and likely the Iuchi as well recognize the power and authority of the Lords of Death, I find myself wondering how they interact with the Meido's Judge of the Dead/Damned, Emma-O. Will they be deputized by the fortune of death to help him resolve the backlog of mortals? I can see them being given a court on par and with equal standing to the nine Kings of **** and given jurisdiction over the Unicorn Clan, their vassals, the wandering Ujik, the Tegensai, Burakamin/Hinin, and Gaijin who die while in the lands of Rokugan.

On a different track, Toshigoku, the realm of slaughter comes across as a cynical take on Valhalla. While most of the empire would view constant battle to be sinful, I could see some such as the Matsu, Moto, and a few others as viewing it not as punishment but as a reward and a paradise in its own right. Perhapse someone can enlighten me as to the source material. I would not surprise me that Toshigoku is a Sinicized version of Valhalla much as Fujin(wind demon/god) and Rajin/Raiden(thunder/lightning demon/god) are believed to be Japanize versions of Aeolus or Boreas and Zeus, respectively. The Greeks heavily influenced Buddhism along the Silk Road and the Vikings did make it down the Volga River Valley to the Caspian Sea, so it would not surprise me that the Norse legends also passed East via merchants and traders.

Finally, the introduction short story was hard to follow and confusing to say the least. The improper use of pluralization didn't help either. About all I got from it was that the shrine's kami wanted to effectively be left alone.

In older eds after the plot advanced, the lords eventually worked with Emma-o and were more or less accepted as fortunes in the rokugani religion iirc

edit: Checked the l5r wiki, they eventually become minor fortunes having a tense working relationship with Emma-o after a stint on fu leng’s side

Right, in the previous timeline they had initially cursed the Moto for abandoning them, but a Moto hero (I do not remember which one at the moment) was able to propitiate them and arrange for them to "join" the Rokugani system by working for Emma-O and being recognized as fortunes.

However, I am not sure this is still the case in fluff. One of the 5E fluff pieces, " Rule from Horseback " indicates that some Moto still venerate them in this continuity. Moto Chagatai thinks of something as an omen from the Lords of Death. An Ujik shamaness from a vassal family to theirs is even more upfront:

"I serve the Lords of Death,” she snapped. “Nothing I do is for your benefit, Moto Chagatai.” The family name was a reminder: Khojin’s mother was no Moto, no kin to him. Ujin Hogelun came from one of the lesser Ujik families. They were nominal vassals to the Moto, although in the free-spirited Unicorn Clan, such bonds of vassalage were mainly theoretical."

Plus, the same story features Moto Chagatai's sister having a household including two husbands and another wife - something unthinkable to most of Rokugan. It is likely that the other Moto in the hinterlands have adopted little of the traditional Rokugani culture or left their traditional religion wholly behind.