Overdrive

Overdrive is a Japanese Yume Nikki fangame that begins with a girl named 323 in a laboratory-like room she does not want to leave. By entering the capsule machine in the room, she can travel to a place called the Outer World. Her goal is to collect every Concept in the Outer World. An unlockable character, 543, is a boy who remains in a patient room and does not want to leave; he becomes available after the player finds a way to meet him in the Outer World.

Overdrive begins with 323 in a laboratory-like room, unwilling to leave until she enters a capsule machine that leads to the Outer World. There, she searches for every Concept and may eventually encounter 543, an isolated boy whose meeting unlocks him as a playable character.