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, 24 April 2012
Relevant Rules Text:
Hida Yamadera
Reaction: After Yamadera enters play from a province: Refill it face-up.
Plains of Otosan Uchi
This province holds two Dynasty cards; do not reveal the second card in the Events Phase this card enters play. You decide each time which card slot is revealed, resolved, or refilled first.
Question:
If Hida Yamadera comes into play from a province with Plains of Otosan Uchi attached, do you refill both cards that it holds face up? And if so, do you discard the card that wasn't Yamadera?
Jon Palmer (rules official), 24 April 2012
Relevant Rules Text:
Hida Yamadera
Plains of Otosan Uchi
Question:
If Hida Yamadera comes into play from a province with Plains of Otosan Uchi attached, do you refill both cards that it holds face up? And if so, do you discard the card that wasn't Yamadera?
"Refill" is something that only happens when a province (or in the case of Plains of Otosan-Uchi, half a province) is empty. You would only refill the card slot from which Yamadera entered, face-up.