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.
A player, 24 April 2012
While you control a Winter card, other players' cards' effects will not negate this Personality's movement. Reaction: After engaging, if any enemy units are at the current battlefield, bow this card: Move this Personality there.
Political Open: Target another player's Personality: His controller chooses to either pay 4 Gold, lose 2 Honor, or do neither. If he did not pay 4 Gold or lose 2 Honor, the Personality may not be assigned, and will not move, into attacking armies.
(Emphasis mine)
A personality (for example, a Qalyar) with a Winter Sled attached is target by Yasuki Daiki's Open ability, and the controller of Qalyar with Winter Sled chooses neither paying gold nor losing honor. Therefore when its controller declares an attack later that turn, that Qalyar with Winter Sled may not be assigned. But Winter Sled's controller has a Winter card, and later he tries to move Qalyar.
Does Winter Sled's "will not negate this personality's movement" override Daiki's "will not move " effect? Since "will not move" is prevention but different from negation, the answer apparently would be no. Am I correct?
Jon Palmer (rules official), 24 April 2012
(Emphasis mine)
A personality (for example, a Qalyar) with a Winter Sled attached is target by Yasuki Daiki's Open ability, and the controller of Qalyar with Winter Sled chooses neither paying gold nor losing honor. Therefore when its controller declares an attack later that turn, that Qalyar with Winter Sled may not be assigned. But Winter Sled's controller has a Winter card, and later he tries to move Qalyar.
Does Winter Sled's "will not negate this personality's movement" override Daiki's "will not move " effect? Since "will not move" is prevention but different from negation, the answer apparently would be no. Am I correct?
You are correct. "Will not move" is stronger than negation, and therefore Winter Sled will not allow the Personality to move.