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, 10 March 2012
In regard to this question/answer: viewtopic.php?f=59&t=96323&p=1273215&hilit=kahoku#p1273215
I must respectfully disagree with the answer. Yes, the effects are separate, and if a card redirected ranged attacks then it would only work with the second half of Kahoku’s ability. But, the card in the question used as an example is Chugo Seido. Chugo Seido reacts to targeting, which is done before the force reduction and long before the ranged attack.
If I am wrong, please explain in detail as I am training to be a head judge and need to be able to explain these things clearly. Thank you.
Brook Cunningham (rules official), 10 March 2012
In regard to this question/answer: viewtopic.php?f=59&t=96323&p=1273215&hilit=kahoku#p1273215
I must respectfully disagree with the answer. Yes, the effects are separate, and if a card redirected ranged attacks then it would only work with the second half of Kahoku’s ability. But, the card in the question used as an example is Chugo Seido. Chugo Seido reacts to targeting, which is done before the force reduction and long before the ranged attack.
If I am wrong, please explain in detail as I am training to be a head judge and need to be able to explain these things clearly. Thank you.
You are wrong, but only as of Emperor Edition if that's any consolation.
Since all required targeting has been moved to constraints as of Before the Dawn, targeting for Ranged Attacks as of EE is no longer required. It occurs in effects, just before resolving the Ranged Attack effect, so it would in fact be after the targeting for, and application of, the Force penalty from Kohaku's ability.
From Ranged Attack: "Ranged Attack targeting occurs during action resolution and so is not required. In other words, a Ranged Attack’s target or targets need not be legal or exist in order to announce the action."