Mokuyo Kumikyoku (2002)

A closed-room mystery where five women gathered in memory of a mysteriously dead female writer to unravel the mystery behind her death. Based on the novel of the same name by Riku Onda, directed by Tetsuo Shinohara.
Four years ago, an actress/novelist died of overdose. Since then, five women who were her friends gather around once every year to recollect her memories. However this year, they receive flowers with a strange message which insinuates that her death could have been a murder.