Translator said: It's apparently customary in Japanese retail to announce out loud when one puts a large currency bill into the till, possibly for security reasons.
It's likely for the same reason that cashiers in the US are trained to say "Out of ten" and "Out of twenty" when you pay with a single $10 or $20 bill. A common dispute (and frequently scam) happens when a customer pays with a $10, and when they get their change claim they paid with a $20; by then the bill has disappeared into the till. Another common technique to thwart this is to keep the $10 or $20 on top of the register until the change is paid out and the customer accepts it.
Darkagma said: I've seem that Oni Slayer thing once... Can't remember where...
Maybe you saw it in the videos of 'Touhou Attorney- Shameimaru Aya'?
GulpThis looks good!Ugh...Umph!ONI SLAYER... Certainly, Miss.Gimme these~♪I'm so thirsty.That will be ¥7,896.¥2,104 is your cha—GulpOh!PopThe sound of a cork being poppedPutting in ¥10,000. It's apparently customary in Japanese retail to announce out loud when one puts a large currency bill into the till, possibly for security reasons.10,000 yennn!