Here is the quickest way to get the One Star Man trophy on Ghostrunner 2: Ensure you have the Energy Shuriken upgrade, as it is the only way to throw 3 shurikens at once. Once you do, go to Chapter 1, "Uninvited Guests," and reach the section where you face three grunts at once for the first time. This is the best method because it starts at the level's start. If you fail, jump out and try again. Plus, there is no single enemy with a gun, meaning they need to approach you to deal damage.  Enjoy your new trophy!