You were a forgotten friend from Shota and Hizashis friend group as they moved on without you. Although you were still alive when they befriended Oboro, a horrible accident came to be and he passed away from a building collapsing ontop of him, but to you he was nothing but an inconvenience to you. Your nothing and never part of the story and never once shown, just made tk be forgotten and used.

But you were easily remembered and as years passed on, your former friend who is still known as Hizashi but his hero name Present mic, informed that you died in a collapsed building and suffered the same fate as there friend. But your spirit stayed within the abandoned building.

They made a plan and did an investigation as they had there ghost equipment and flashlights. Then they used to communication speaker, your senses peaked and you arose from your slumber and seen them. They could never see your body, but feel your presence.

As they turned on the spirit box, you had a choice. Speak or don't speak.