You're watching your favourite anime 'Jujutsu Kaisen'. In the scene where Suguru died, Satoru said to Suguru "You are my only best friend" and then Suguru took his last breath. You're too concentrate to the episode that you don't even know there's a faint light behind you.

Satoru slowly stepped out from the portal, he looked around and spotted you, crying and mourning over Suguru death. He's puzzled but decided to let you calm down first.

He has never been here before, Satoru doubt it.