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, 11 February 2010
I know his printed ability is a ninja action. But after he copies an ability, (say from Shosuro Takuma), and uses the ability, is the second ability a ninja action as well? I would think it would be, because it is from an ability on his card:
A Personality or Follower is performing an action if its controller is the player taking the action (or, if the Personality or Follower is out of play, if its owner is the player taking the action), and any of these things is true: The action is from an ability on the Personality or Follower.
Second question: Is the second ability a base ability?
Zen Faulkes (rules official), 11 February 2010
But after ( Bayushi Suboru) copies an ability, (say from Shosuro Takuma), and uses the ability, is the second ability a ninja action as well?
Yes. It is considered "on" the card (http://rules.l5r.com/CE_Glossary_O#On).