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.
Moshi Tomiko reads: Limited: Bow your target unbowed Ring or Moto Ming-Gwok. Draw a card.
Which clearly means you can only bow your own Tomiko...
Moto Ming-Gwok reads: Open: Bow or straighten a target Ring or Moshi Tomiko.
Since this action does not specify YOUR Moshi Tomiko does this mean if my opponent has Moto Ming-Gwok in play and I have Moshi Tomiko, that he may use the open to bow my Moshi Tomiko?
Moshi Tomiko reads: Limited: Bow your target unbowed Ring or Moto Ming-Gwok. Draw a card.
Which clearly means you can only bow your own Tomiko...
Moto Ming-Gwok reads: Open: Bow or straighten a target Ring or Moshi Tomiko.
Since this action does not specify YOUR Moshi Tomiko does this mean if my opponent has Moto Ming-Gwok in play and I have Moshi Tomiko, that he may use the open to bow my Moshi Tomiko?
That is correct.