Looking to translate a game

I got the program and the means to do so. My only issue is that the game I am looking to translate is a paid game.
https://www.dlsite.com/ecchi-eng-touch/work/=/product_id/RE256313.html

Am i still allowed to translate the game? I'm doing so with the intention of making an English version available for the public but not exactly too sure what the process might be since people need to pay for the game first.

You are allowed to buy the game and make translation, then you can give people the translation files with instructions how to apply them to the game to translate it themselves. That would make it so everyone has to buy the game first and then they get translation from you and nothing gets stolen.

You're not allowed to send people patched full game as this is probably just theft.