Maybe you should listen to this podcast/story. https://www.npr.org/2018/06/12/619207707/the-apology-broker
It's about a Japanese woman who tries to get Japanese companies to apologize to former POW's from WWII. In it, it talks a bit about Japanese apologies in the second half of the 20th century.
They talk about one of the first used the phrasing "makoto ni ikan" / "誠に 遺憾" which means "True Regret". However it was criticized for being too unemotional or neutral. So in another apology they used "Hansei" or "反省" which was critized as not a real apology, they were just going to "think about" what they've done. But in Japanese it means to truly take your mistake or wrong doing to heart. Anyways, after being criticized for their apologies so much Japan decided to stop.
How ever wikipedia has a page of apologies made by different Japanese government officials over the war and it seems a lot were made.
That's not to say Japan is perfect, I think they should come out more strongly and clearly in apologies for certain things (comfort women) and they should probably stop going to the Yasukuni Shrine. But I also think that beating Japan over their "lack of apologies" and war reparations(which were given to Korea) are convenient ways to score political points for elections.