A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from the Wayback Machine (its copy), so posts 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.
In another post about Isawa, was said that spells that isawa cast never enter play, sooo...
Can those spells be recovered with The kami watch over me?
When Isawa cast a spell, can I use the reaction on Kyuden Tombo to draw a card?
And about Asako Bairei:
Can i use his second abilitiy to draw a card after a surged unit containing spells returns to play?
If the first answer is Yes, does this happen in my turn or in my opponent's turn?
Can those spells be recovered with The kami watch over me?
I'm going to say no, because it did have effects that resolved.
When Isawa cast a spell, can I use the reaction on Kyuden Tombo to draw a card?
I'm going to say no here, too. Look at action cards: action cards don't enter play, but I doubt anyone would want to argue that you could use Kyuden Tonbo after resolving the effects of an action card.
Can i use (Asako Bairei's) second abilitiy to draw a card after a surged unit containing spells returns to play?
Yes.
(D)oes this happen in my turn or in my opponent's turn?
When the unit returns to play, before your turn (Suitengu's Surge text).