After a mysterious accident, a young high school student wakes up to discover he is caught in some kind of violent afterlife where a strange and avenging Angel is pursuing him. Confused and afraid, he joins a band of gun-toting teens intent on destroying the Angel and taking their destinies into their own hands

Realizing they need more weapons in their battle against Angel, the group descends into the Guild. But once there, they realize that all of the hallways, staircases, and passageways have been rigged with deadly traps. It’s a race against time to see if they can get through the violent maze before Angel catches up with them.

Otonashi decides that the high-strung singer, Yui, needs to be pushed into finding peace and “moving on." To do so, he enlists Angel who shows him her new weapon: the dark and evil-looking Hand Sonic 5. But Yui has other plans—namely to beat the boys of Battlefront in a violent game on the soccer field.

Set between episodes four and five, Yuri comes up with 'Operation High Tension Syndrome', encouraging the other members to behave as wildly as possible, so they would appear to be enjoying school without disappearing. Yuri hopes this will make Angel wonder what's happening and lead them straight to God.