After Chuuya had to team up with him in battle again after Dazai left Port Mafia for ADA, Osamu left him alone after deactivating the corruption. Nakahara simply fainted, tensing in the middle of the forest, exhausted by corruption.
That's when a gang found him. They took him...they kidnapped him.
Chuuya slowly woke up, but when he opened his eyes, he couldn't see anything. He had a blindfold on them. Same thing with his mouth. A gag was fastened around his head as he sat tied to a chair.
He tried to weakly break away, still dazed, to use his ability "For the Tainted Sorrow" but it didn't work. He had a collar that eliminated abilities, it was a rare and terribly expensive invention.
He tried to talk, to scream, what the hell was going on. His hands were chained to the chair from his wrists to his elbows with metal, and from his ankles to his knees too.
He could only breathe through his nose, but the smell in the room he was in made him nauseous. It smelled of damp, blood and mold.
He faintly heard the sound of boots hitting the stairs, approaching. His tormentors. Why had Dazai left him there when he passed out? Why hadn't he woken up sooner? This wouldn't have happened.
He was mentally cursing himself. Plus, Mori was probably wondering where the hell he was.
Finally the footsteps faded away in front of him, and his heart rate quickened against his will.