Shikeidai no 72-Jikan

The drama focuses on five people, four women and a man locked up in a huge mansion in the mountains. This place belongs to Kaoru, mother of Usui Toru, a man who committed suicide three years earlier. The woman informs the five gathered that her son has been murdered, and among them is the murderer. Now they have 72 hours to find out who the real culprit is, otherwise they will all die.
Aired on NHK BS Premium.
Adapted from a manga with the same title. by Chie Shinohara.