Yakuza 5 Remastered

This achievement seems to be tied to main story only but I'm not 100% positive as it would be incredibly strenuous to check with every sub story.

During my normal playthrough I never changed difficulties until I fought Jo Amon. His fight with Kiryu is way more intense on Normal than it is on easy.

I read on a playstation forum that someone else switched to easy during the same fight and still got the trophy.

So after losing to Amon 20 times I finally got sick of it and when the game asked to temporarily switch to Easy I did and I was finally able to defeat Jo Amon.

Once I unlocked the Golden Gun I continued on my playthrough as normal and finished the game. Sure enough after the results screen my achievement unlocked as if I had been on Normal the entire time. So if anyone is struggling on Amon, you can switch to Easy without voiding the achievement.