In Ghostwire: Tokyo, you can upgrade your skills with normal skill points, but you’ll need Magatama to upgrade them further. Our Ghostwire: Tokyo guide explains where to find Magatama quickly.
To get Magatama, you’ll need to seal yokai that you find around Shibuya. You can find yokai quickly by completely side quests. Each side quest is marked on your map with a green icon. You can even hover the side quest to check the rewards, as not every side quest will reward you with a Magatama.
Side quests vary. Some will have you chase and follow a yokai, others may have to search a building, fighting enemies in the way. Either way, it’s important to stock up on Ether and materials before you start, so you’ll be prepared to fight anything that pops up. Any buildings that you have to search through for a side quest may also have antique treasures to sell to the ghost cats, so make sure to keep your eyes out for those as well.