How to Hack EBOOTs

[flamethrower]

I mean, this is a gigantic topic and I'll expand this later. Or I won't. For now, this is how to get started with it.

You can full extract your ISO with 7-zip. Or at least I think you can.
You can also full extract it with UMDgen, and UMDgen can also do partial extract, so that's what I'll recommend. Get UMDgen here: https://www.romhacking.net/utilities/1218/

Anyway, you need to extract EBOOT.BIN. I think that goes without saying.

The next step is to decrypt the EBOOT. To do that, use deceboot. Get that here: http://www.romhacking.net/utilities/1225/

Now that you have a decrypted EBOOT, feel free to inspect its contents with your hex editor. For Japanese text, I have seen SHIFT-JIS, UTF-8 and UTF-16LE, although UTF-16LE is somewhat less common than the other two.