It's an anime adaptation of the second game in Front Wing's Grisaia trilogy.
The Fruit of Grisaia became a 13-episode anime in 2014 and
The Eden of Grisaia became a 11-episode anime immediately after Labyrinth, starting the week after this TV film aired. Put together the two 2015 releases and that's effectively a second 13-part season, except that its first two episodes have been combined into one TV film.
I've just done some googling and it sounds as if the original game here has been cut down so savagely that I'm not sure if you'd call it an adaptation.
The Fruit of Grisaia (anime) glossed over plenty of its source material, but at least it was recognisably the same story. This isn't. They've taken its spine (Yuuji's upbringing) and stripped out everything else, including major characters (Asako) and plot threads. It's a shame about Asako, I think. She was hugely important to Yuuji and we learned a bit about her in
The Fruit of Grisaia, even though by then she was dead. Maybe her story will get added into Eden instead?
None of that really matters, though. This is a good TV film. Its narrative works and the story it tells is traumatic. I haven't played the game, so I don't really care about how that maps on it.
It's a prequel, telling us how the ice-cold killer Yuuji got that way. However it also has a framing story, in which Yuuji's applying for a promotion and having to have an interview with his boss. She asks about his past. He says it's all in the documents, but she makes him talk about it anyway. (There's also a post-credits scene with the girls of Mihama Academy, taking advantage of a rare moment of Yuuji sloppiness. You wouldn't call his error sloppiness under any normal circumstances, but the Mihama girls are a long, long way from being normal.)
Anyway, Yuuji. The Yuuji we know and love is reptilian, with the emotional engagement of an incoming meteorite. Once upon a time, though, his sister Kazuki thought he was a kind, gentle child whose only problem was that he was too nice. How did he get from one to the other? The answer is here and it's ugly. I'd known the broad outlines of his childhood from
The Fruit of Grisaia, but I hadn't known it was this vile. The story involves a sympathetic but manipulative and slightly incestuous sister, a vicious parasite of a father, a spineless mother who spends all her time saying 'sorry', a paedophile, suicide, rape, a terrorist training camp, a military assault with everyone getting machine-gunned and of course Yuuji being turned into a hit man. I particularly liked the fact that they don't try to portray him as a Nice Assassin. You know, the kind who's okay because he only kills bad people. There's none of that here. Yuuji's boss is the paedophile and his victims include judges, political leaders and investigative journalists.
The incest is left open. We don't see anything happen, despite Kazuki's eyebrow-raising conversation when they're in the bath together, but the scene ends with a fade to white and "I learned all sorts of things from my sister".
The rape ends in Yuuji's first murder, although technically it's possible that the guy was still alive at that point.
Yuuji only makes one friend who's not his sister. (He has problems with friendship in general, although he finds it easier when they're girls.) This friend is Marlin. She's nice. Naturally this goes somewhere horrific, then takes a right turn into a different kind of darkness before ending up in a very dead end. I'd like to think that Marlin survived and will return in Eden. That would be nicer than the alternative.
I've looked up the meaning of the word "grisaia", by the way. It's a distortion of the French word "grisaille", which means painting in (near?) monochrome, often in imitation of sculpture. Apparently a closer transliteration would have a different last syllable, though, and the reason for the change is in the third game. So now you know.
This story is a monstrously horrible series of events, but it avoids the Gratuitous Tragedy Porn trap because Yuuji's so unsentimental. He just gets on with it. A more sensitive protagonist could have made for cheap tearjerking, but Yuuji isn't asking for anyone's sympathy and is going to end up sticking pens in people's necks. It's strong stuff. The only downside of watching this TV film is that its events are so powerful that I'm sure the Eden episodes will be in danger of seeming anticlimactic, with the relatively stable life of Yuuji and the girls at Mihama Academy. I'll be there to see how the story continues, though. I'm looking forward to it.