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, 3 July 2013
Relevant text:
The Perfect Moment: After the end of an Attack Phase in which you were the Defender: Create an additional Attack Phase with the previous phase's Attacker as the Defender. During this Attack Phase, you will not destroy more than one of the Defender's provinces and your Personalities may not assign and will not move unless they are Paragons or Battle Maidens.
Akodo Dairuko: Reaction: Even if Dairuko is bowed, before the resolution of a battle at her battlefield: Dairuko rallies her troops. That battle's resolution will not bow cards in your army.
Now if I Perfect Moment after an attack and use Dairuko's r at the end of the battle, am I able to TPM again and assign Dairuko again?
Brook Cunningham (rules official), 4 July 2013
Relevant text:
The Perfect Moment: After the end of an Attack Phase in which you were the Defender: Create an additional Attack Phase with the previous phase's Attacker as the Defender. During this Attack Phase, you will not destroy more than one of the Defender's provinces and your Personalities may not assign and will not move unless they are Paragons or Battle Maidens.
Akodo Dairuko: Reaction: Even if Dairuko is bowed, before the resolution of a battle at her battlefield: Dairuko rallies her troops. That battle's resolution will not bow cards in your army.
Now if I Perfect Moment after an attack and use Dairuko's r at the end of the battle, am I able to TPM again and assign Dairuko again?
Indeed you may. Nothing prevents the interaction you describe.