By the sound of it, you have a protein allergy. That is, you are allergic to a specific, or set of specific, proteins. When the proteins are denatured, you seem to not be allergic. This can happen at high temperature, low pH, or sometimes through oxidation. There’s a substantial amount of research on this if you want to look it up. But, for it to be particularly constructive, first you would need to determine to which protein you are allergic

> I'm allergic to fish...

I'd guess that your allergy is to some class of proteins in the fish - and that the production steps for dried bonito (and maybe the time required) denature or destroy those proteins.

I was at a fish ramen place in Tokyo, they had a bonito block with a hand operated shaver, looked like a giant pencil sharpener.

Next to the ramen they would serve the bonito flakes contained in a small net, And suggest to soak for 10 seconds, but no more than 30 because the flavor would be too intense.

*1882

Is this supposed to be some insightful criticism? They've been making the same product for 144 years, and managed to retain the technique from an era only 14 years prior. That's an achievement.

If a place started doing the same in 2017, guess what, they could still make it like they did in the Edo period.

Apart from a bit of machinery for lifting, and starting with frozen fish (which they thaw first anyway), it's basically all manual labour, including adjusting the fire temperature.