Does viewtopic.php?f=59&t=101661 reverse viewtopic.php?f=59&t=95539&p=1266380&hilit=koshin+keep#p1266380 since there is only one legal target for the additional ranged attack granted by Koshin Keep's effect?
Koshin Keep
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.
Does viewtopic.php?f=59&t=101661 reverse viewtopic.php?f=59&t=95539&p=1266380&hilit=koshin+keep#p1266380 since there is only one legal target for the additional ranged attack granted by Koshin Keep's effect?
No.
The difference between the two is that Plains of Glass specifically overrides the only functionality of the Conquerer rule - it has to be allowed to be taken twice, or it could not work at all (similar to how Hidden Defenses doesn't need explicit wording to overcome the Rule of Presence).
Koshin Keep doesn't allow any such thing, it just sets a requirement that you target the same Personality. You can play another No Hiding Place, or, y'know, shoot someone who isn't at home to begin with.
On: Koshin Keep