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, 29 October 2007
Red Leaf Cut reads: Reaction: Before Focus Effects resolve: Discard a focused card; its owner may focus an additional card from his hand or focus pool.
Now if I use the reaction to Red Leaf Cut, my opponent focuses an additional card. Now since red leaf Cut doenst specify focus face up, the card is focused face down. However, since the focus effects dont arent revealed until AFTER the cards are already flipped face up, when do I reveal the new card or is it never revealed and not add its focus value and focus effect (of the new card) doesnt occur?
Chris Fuchs (rules official), 30 October 2007
http://rules.l5r.com/Challenges_and_duels
E: Both players reveal (turn face up) all cards in their focusing area.
After this point, any cards that enter focusing areas in the duel do so face-up. [ADDED 24 Jul 07]