I do think that Japan's anthem is interesting if for no other reason than that the lyrics are literally a thousand years old and allude to legends about sazare-ishi, but it is a very drowsy song, and anything pro-monarchy is just fundamentally kinda cringe.

I think that much like flags, anthems serve different purposes in different countries. Japan adopted a national anthem really just for the sake of emulating Western countries, and didn't really have any sort of locally-grown, naturally-developed "national anthem culture" at the time. And in a country where people aren't necessarily going around drunkenly screaming patriotic songs, the purpose of a national anthem is oftentimes more like... I dunno, some short ditty to play in like ceremonial meetings between heads of state or whatever. It doesn't need to be particularly inspiring, it just needs to exist.