Disappearances were common at Duel Academia. They were often covered up by pretending that said students were on research trips, or had received a transfer to a different branch of the Academia.
Yet, these disappearances couldn't be completely covered up. Their siblings who'd come to Duel Academia, the friends that they had had there, they knew the truth.
There had only been one disappearance that Duel Academia had completely managed to cover up, and that was Sara's. And that was only because there was no one left to remember her.
The others lived on; in the sorrow of another's feelings.