Boku ga Kimi wo Korosu made

The story takes place in Japan, in a world where murderers are imprisoned in a closed space and executed in the same manner as the victims, and the execution is broadcast live.
The newly sentenced death row inmate, Kaoru Oda, is a murderer who strangled his lover to death in a love affair.
Kohei Mizutani, a prison guard, is selected and ordered to carry out Oda's execution simply because of their similar physique.

Note: Includes one extra chapter.