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, 20 May 2010
If my opponent plays Unfamiliar Ground and bows my guy, can I react with Setting Sun Strike from that?
Unfamiliar Ground text: Terrain Battle: Bow each card with 5 or higher Force now at this battlefield. If a card's effect destroys this Terrain iduring this battle, straighten all cards it bowed.
Setting Sun Strike text: Heroic Reaction: After another player's action targets your Hero Personality during a Combat Segment: Give the Hero +3F. Straighten him before this battle's resolution.
My question basically comes down to this: does Unfamiliar Ground target each card that it bows?
Zen Faulkes (rules official), 20 May 2010
(D)oes Unfamiliar Ground target each card that it bows?
No.
http://rules.l5r.com/CE_Glossary_T#Targeting: "The word 'target' must appear as a verb or an adjective for the procedure to be considered targeting" (emphasis added).