A woman has set up a small gallery in her Tokyo home to exhibit mementos of an executed killer and a replica of his prison cell in the hope that it will encourage visitors to consider how similar crimes might be prevented.

The items on display include the investigation and trial records of Norio Nagayama, who was hanged in 1997 for shooting four people in 1968 when he was 19, as well as some of his literary works, as he became known for his writing while on death row.

In addition, his library of more than 150 volumes, including dictionaries and books on law and philosophy, show how diligent Nagayama — a neglected child from an extremely poor family — became in his studies following his arrest and imprisonment.