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.
What is the result of Kageki's duel? (What happens to the winner/loser, if anything?)
"Enters play paying 4 less Gold if you are a Ratling player. Battle: Target an enemy Personality: Kageki duels him. Both Personalities use Personal Honor as their duel stat. If the target is dishonorable, the first card you focus adds its Focus Value twice when totaled during duel resolution."
What is the result of Kageki's duel? (What happens to the winner/loser, if anything?)
"Enters play paying 4 less Gold if you are a Ratling player. Battle: Target an enemy Personality: Kageki duels him. Both Personalities use Personal Honor as their duel stat. If the target is dishonorable, the first card you focus adds its Focus Value twice when totaled during duel resolution."
As a general rule, any duel you see that doesn't have a stated cost for refusal and/or consequence for losing in the Oracle is unrefusable or fatal, respectively. So Kagaki's duel is to the death.