In Amazon's The Man in the High Castle, whenever Kotomichi comes into Mr. Tagomi's office, he says something just before he opens the door. It sounds sort of like "Christmas" to me, but presumably it's not that, and the subtitles just say [speaking Japanese]. What is he saying, and what does it mean?
Assuming you're talking about scenes like the one in season 1 episode 8 (End of the World), where Juliana comes in late to work and is confronted by Kotomichi - he says "Shitsurei-shimasu."
Juliana: "Mr. Kotomichi, please forgive me if I've done something to offend you."
Kotomichi: "You have done nothing to offend me, Miss Crain. It is your presence. It brings danger. You cannot know what he risked giving you employment."
Juliana: "Look, I don't wish to harm him."
Kotomichi: "And yet you will." (opening Tagomi's office door) "Shitsurei-shimasu! (Excuse me.)"
Tagomi: "Good morning, Miss Crain."
In this case it means "excuse me" and is used when entering someone else's space, or leaving.
It should be pointed out that almost all polite Japanese ends in "-masu" and rhymes with Christmas so you could have heard something else in a different scene.