In Multiplayer games, when one controls Ikoma Yasuko experienced, and a player has been invited by both the attacker and the defender but has assigned no units, is there any restriction on whether Ikoma Yasuko experienced may move someone from that player's home into the attacker's or the defender's side? (presuming of course that Ikoma Yasuko experienced's controller meets the conditions under the Rules of Presence and Relevance)
Ikoma Yasuko experienced
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Effects that move, assign, or create units controlled by another player on a side at a battlefield can establish the other player's allying status, keeping in mind that he or she must currently invited to ally by the appropriate leader for those effects to work in the first place. [ADDED Jul 23 07]
You can see the whole run-down on Allying in the Comprehensive Rules.
There is nothing that requires an invited player to be the one who initiates a move-in effect that establishes him as an ally. Ikoma Yasuko can certainly force the issue, and whoever used her ability gets to decide exactly which army at the Battlefield the moved unit gets put into.
On: Ikoma Yasuko