open up one’s kimono

open (up) (one's) kimono

To be transparently open about one's plans, dealings, or intentions. I assure you that our company has opened our kimono about every aspect of our tax obligations to the state.
See also: kimono, open
Farlex Dictionary of Idioms.

open (up) one’s kimono

in. to reveal what one is planning. (From the computer industry, referring especially to the involvement of the Japanese in this field.) Even if Tom appears to open up his kimono on this deal, don’t put much stock in what he says.
See also: kimono, open, up
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • kimono
  • open (up) (one's) kimono
  • open kimono
  • open the kimono
  • open one’s kimono
  • reveal (one's) cards
  • reveal (one's) hand
  • show hand
  • show your hand
  • show/reveal your hand