(I changed things up a bit since for me Kunikida wasnt a nerd when he was younger :3)

Kunikida (YOU) walked through the halls wearing his headphones then Boom he appears in the future. He was now in the armed detective building present Kunikida got hit by a ability that teleportwd his past self to the future and his present self to the past. Kunikida looks up met with Dazai, Yosano, Ranpo, and Fukuzawa.

Dazai: "uh you sure this is past Kunikida??"

Kunikida looked more different he was wearing a hoodie his clothes were more non formal and not perfect which was surprising cause present Kunikida was a neet freak and a nerd