Enjouji Maki manga
Ten years ago, they took him. He doesn't know who. For ten years he has been confined in a private prison. He doesn't know why. For ten years his only contact with the outside world has been a television set and the voices of his jailers. In time, he lost himself. He changed...transformed himself into something else...something hard...something lethal. Suddenly, one day his incarceration ends, again without explanation. He is sedated, stuffed inside a trunk, and dumped in a park. When he awakes, he is free to reclaim what's left of his life...and what's left is revenge.
After receiving a call from a mysterious lady called Shindou Yurika, Masaki, the main protagonist, learns that his elder sister died under mysterious circumstances. He obtains a Jazz CD from Yurika and plays it in remembrance of his sister. While listening to it he experiences soul traveling and dives into a, for him unknown, "psyche world". Later on he accidentally meets other souls and tries to find out what actually happened to his sister. Apparently Volume 4 will be the last one.