Just beat the game’s true ending.
The game is really quite similar to the previous Date A Live game Rinne Utopia, with more characters and volume.
The game takes place after volume 7 (while Rinne Utopia takes place after volume 4), so there are 3 additional Spirits: Kaguya, Yuzuru and Miku (well, Kaguya and Yuzuru are twins).
Since Mana has recovered (she was heavily wounded in volume 4), she also appears in this game, but just a sub-character. Mikie that is more prominently featured in Date A Strike spin-off manga also made an appearance as well.
Just like Rinne Utopia, player has to first get all good endings of the visual novel characters (Tooka, Origami, Yoshino, Kurumi, Kotori, Kaguya, Yuzuru, and Miku) before being able to go to the true ending route that focuses on the brand-new characters.
So 8 initial routes to go through (5 in Rinne Utopia). The interesting thing about Kaguya and Yuzuru is that they start with the same route (you can’t choose them separately), then you can choose between one of the two near the end.
The two brand-new characters in this game are white and black Ars, although white Ars is the one player mostly interacts with. Since white Ars thinks that ‘Ars’ is just a surname, Shidou gives white Ars the name Maria (since her design looks like a sister). Black Ars also has a name but it’s only revealed near the end.
Also, as we beat more endings, Maria gradually has a few extra lines in the next playthroughs to keep the repetitions somewhat fresh.
I forgot what they did with Rinne Utopia to make the repeating world possible, but this time the plot device they use is more straightforward and that’s virtual reality.
Believe it or not, Ratatosk made ‘Koishite My Little Shidou 2′, a sequel to galge that was made to train Shidou in dating the Spirits. This time however it’s not just a simple galge but super simulated virtual reality, as such it can only be run with Fraxinus’ supercomputer, and it’s where the game mostly takes place.
So Maria and black Ars are not real Spirits but artificial, digital Spirits (i.e., computer programs). They are mostly 2 separate entities (so they’re not one character with split personality). They also did something interesting with the true identity of Maria. The common illustrations of Maria and black Ars do not show them in astral dress form btw, since the design is kind of spoilers.
The basic premise is that Maria mysteriously appears in the game world while Shidou is trying out the game, Shidou gets trapped, and then all the girls also log into the game to try to save Shidou. They face Maria, who turns out to be non-hostile and simply ‘wants to learn about love’. In the end Shidou and the girls agree to show her the answer by living in the game world as they would normally in the real world (there’s time difference between the game world and real world so that it’s no problem for them to stay for long time in the game world).
So Maria begins to observe how Shidou dates with the girls. Maria, having control of the game world, can reset the world and even manipulate the settings to create unusual date events, such as Tooka becoming a school doctor, Kotori a magical girl, Kaguya and Yuzuru succubus etc. This basically allows ‘dream situations’ that are not possible in the main story.
Here’s a spoiler of the true identity of Maria btw (highlight the next text): she’s Fraxinus AI personified, thanks to the contact with black Ars. She can be considered as Fraxinus herself. When Kotori and Reine mentioned to Shidou that Fraxinus is equipped with high-level AI, she is the one they are talking about. She’s also the one that ‘comes up with choices’ during date situations. When black Ars, the artificial Spirit created by DEM organization, broke into Fraxinus’ main computer, the AI trapped black Ars together with herself in the virtual reality world (the Koishite My Little Shidou 2 game) with strong protection. To understand and deal with the unknown enemy she’s facing, the AI collects traced information about the enemy and recreates a version out of herself (that’s why she gains appearance similar to black Ars and a personality). The AI is also locked out of her memories, since she’s also trapped inside. As a result the AI can’t remember anything, except for her purpose. That’s why she wants to know about love, since she’s originally an AI created to support Shidou in love situations with the Spirits. Her astral form design aptly resembles the design of Fraxinus ship. So unlike Rinne Utopia, she doesn’t really ‘disappear’ at the end of this game. In fact, at the very last part of the true ending, she manages to get installed as a virtual assistant app in Shidou’s phone while Fraxinus is under restoration (image) (and that’s why the game is called Ars Install ^^;).
Black Ars spoiler: her full name is 或守 鞠奈 (Arusu Marina). Unlike Maria, her name Marina is not given by Shidou but by her ‘father’ (presumably Wescott)..
So is this game better than Rinne Utopia? I think I would need to read Rinne Utopia again, but I think so. It’s also more straightforward and easier to wrap my head around. The true ending of this game is also quite touching I almost cried.