[richvh]

Spoiler:

YOMI (always capitalized, but if it's an acronym, it hasn't been explained) is an organization made up of the leading disciples of the members of 闇(Yami, darkness), an international group of martial artists seeking power for its own sake. Ryuuto/Odin, as the personal disciple of Yami member 拳聖(Kensei), is a member of YOMI; the other Ragnarok fists were not. After the defeat of Ragnarok, the attention of Yami and YOMI is attracted to Kenichi, and they try to recruit him and Miu into the ranks of YOMI - in fact this has already started in the anime, where Kensei tried to take on Kenichi as his disciple during the mountain retreat training.