Synonyms that are in the dictionary are marked in green. Synonyms that are not in the dictionary are marked in red.
Antonyms that are in the dictionary are marked in green. Antonyms that are not in the dictionary are marked in red.
The other materials are mostly found by defeating enemies while exploring Like a Dragon Ishin's, so getting into many fights is a great way to start building up a supply.
Source: https://gamerant.com/like-a-dragon-ishin-how-buy-forge-make-new-weapons/