Oyakusoku — literally “the promise” — is the standard, well-worn development for a situation, carried out exactly as everyone expected. In Japanese it is also called beta: the stock version, the obvious one, the move you can see coming from a long way off.
You are watching a Japanese show with subtitles. You follow every line. And then a character says something completely ordinary — and everyone laughs. Or another character shouts a single word and the scene is over, and you can tell that was the joke, but not why.
Gap is the pattern where an impression that already exists — built by appearance, by rank, or by how someone usually behaves — is contradicted at exactly one point.
The department head with the hard face, the one everybody quietly assumes writes in clipped functional sentences. Then his message arrives and it is wall-to-wall emoji.