I know this story pretty well already, having read a few books on it. Tokyo Hostess, in particular, was well written and gave a lot of detail.
This documentary starts when Lucie has already disappeared, so there is no background to her life in Tokyo and her job working in the hostess club. It suffers greatly for this, as this is what would make the casual viewer care about her story.
Instead, it's her father, who I find seriously arrogant, who is star of this show. Not playing down that he lost his daughter, and obviously what happened to Lucie was evil, but I just couldn't deal with him throwing his weight around in another country. I know this won't be a popular opinion. Reading that he accepted a cash payment in hopes of a reduced sentence from a friend of the killer makes him look even worse, honestly.
Lucie took a silly risk to make easy money (again, in no way makes what happened to her okay). Father has the air of wealth, so not sure why he didn't just fund her holiday instead of letting her do that. Even a safe country has its issues.