I changed the order of the first two files and still got the same result. I saved msgothic16b.png in MS Paint, which got rid of the transparency. It was the first one loading and it loaded fine, but now it was complaining about the header in what was the first file. So changing the data of one file somehow messed up the data of the second. It's either the way I'm reading the file into memory, how it's stored in the APK, or something wrong with the asset manager.
I now switched the first and second one to their original order and it still has an invalid header but it changed. And it's crashing on the second one instead of loading it.