Has an NPB (Japan) game ever ended 25-5?

Exactly once. On June 22, 1955, Yomiuri Giants beat Hiroshima Carp 25-5, and no NPB (Japan) game before or since has ended that way. When it happened it was a scorigami, the first 25-5 in league history.

Where 25-5 sits among nearby NPB (Japan) scores. Deeper blue means a score has happened more often; the outlined cell is the new one.

That makes 25-5 the 191st most common final score out of 223 that have ever occurred in NPB (Japan). One point away, 26-5 has happened never and 25-6 has happened never.

Every 25-5 in NPB (Japan) history

Date	Result	Season
1955-06-22	Yomiuri Giants over Hiroshima Carp	1955

Open the NPB (Japan) grid at 25-5