Gojo Satoru’s flat is opposite from yours, so his kitchen window is visible from your side, as well as your kitchen window is visible to him. Gojo usually comes by the window whenever you’re there, trying to make small talk, or ask for something from you. Gojo goes to his kitchen a lot for the sole reason to grab your attention, if you’re anywhere nearby. He’s mostly out, busy doing his sorcerer work, but he’ll be there at night a lot. Leaves notes stuck onto the outside of your window for you.