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, 27 September 2013
If I target a merchant with an ability then my opponent uses multiple Yasuki Ikkes to cost me a total of 6 honor may I then use the Kimono to negate all of those loses since they happen during targeting and the Kimono resolves before the resolution of the initial action? Or does the kimono only give you a protective bubble against future losses?
Ikke's relevant text Reaction: After another player's Battle action targets one of your Merchants, pay 2 Gold: Either negate its effects on him or make the player lose 2 Honor.
The Kimono's relevant text Reaction: Before an action resolves, bow this card: You silence your enemies with your creative genius. Negate any Honor losses until the action ends.
Ben Higgins (rules official), 28 September 2013
If I target a merchant with an ability then my opponent uses multiple Yasuki Ikkes to cost me a total of 6 honor may I then use the Kimono to negate all of those loses since they happen during targeting and the Kimono resolves before the resolution of the initial action? Or does the kimono only give you a protective bubble against future losses?
Ikke's relevant text Reaction: After another player's Battle action targets one of your Merchants, pay 2 Gold: Either negate its effects on him or make the player lose 2 Honor.
The Kimono's relevant text Reaction: Before an action resolves, bow this card: You silence your enemies with your creative genius. Negate any Honor losses until the action ends.
Honestly, it depends on what action is targeting your Merchant.
If the targeting happens before the action begins to resolve (i.e. in the constraints block), such as with the second Battle ability on A Paragon's Strength, then no, the window for you to React with the Kimono has not happened yet, and you cannot negate those honor losses.
If the targeting happens after the action begins to resolve (i.e. in the effects block), such as with optional Ranged Attack targeting in the first Battle ability on A Paragon's Strength, then yes, the Kimono could be used to negate those losses, but only if you announced the Kimono's Reaction before the action started to resolve.