I'm still on the "learning Japanese" step, so I am no expert here. However no one else is stepping up here, that means you're left with me! First step would be to identify which game you want to translate which will allow you to figure out what engine you're working with. Once you know what engine it is you can find a decryption program that unpacks the engine. With the game decrypted it should be a simple process of translating the script, not translating the code, and recrypting the result.