15 Year Lie

15 Year Lie (１５年の嘘), also known as 15 Years of Lies, is a movie directed by Taishi Gotanda and produced by Masaya Kaburagi. It was co-written by Taishi Gotanda and Aqua Hoshino, in the legacy of Ai Hoshino and Aqua's attempt to avenge her.

Background
Sometime in the past, Ai Hoshino asked Taishi Gotanda to make a documentary film about B-Komachi. He reluctantly accepted the request and started shooting the film. However, he also wanted to film the real Ai that wasn't covered with lies, which she agreed. It was progressing well, all that remained was filming B-Komachi's live show at the dome when an incident happened: Ai was murdered, and the project was canceled.

A long time later, Ai's secret is published by her own son, Aqua Hoshino. Realizing it is the right time, Taishi decides to restart the project with Aqua's supporting, now it is a movie telling the story about a famous idol's life and hidden details behind her glory.

Purpose
The film is an autobiography of Ai Hoshino's life. According to Frill Shiranui, who had early access to the script, it's an attempt to kill Aqua's and Ruby's father, Hikaru Kamiki.