No. 6 Vol. 4 (manga)

"OUR CHANCES OF SURVIVAL ARE ROUGHLY ZERO PERCENT."

Shion accidentally learning that his childhood friend Safu is under arrest - and all because of him! Not wanting to get Rat involved, Shion sets out alone to save her. But how can he possibly infiltrate No. 6's secure correctional facility and escape with a high-priority prisoner all on his own?