Satoshi Mochida’s profile from the Corpse Party 2: DEAD PATIENT Drama CD Vol. 2. It reads:
[4th Year University Student / 22 years old]
Satoshi was one of the students who had survived Sachiko’s curse as he was trapped inside Heavenly Host Elementary School.
While visiting his sick mother at Amare Patriarcha Crucis Hospital, he found himself locked in.
Also the announcement for the extra chapter, “Satoshi Mochida Part 1″, has the following information for Satoshi:
Heavenly Host Survivor
“Don’t worry, I’ll definitely come back.
So, Mom, just stay here and don’t leave this room, okay?”