This is high-class art.
Okay, here goes:
Nights of Azure mini-review.
Basically what happened is that in the past, a Demon King known as the Nightlord descended upon the world to plunge it into an Eternal Night. He got defeated and sealed away by a woman henceforth known as the First Saint. The Nightlord's blood, the Blue Blood, rained down on the ground upon his defeat and turned people and objects into monsters known as Fiends, creatures who are active only at night, making the world into a "land without night" (which is literally what the Japanese title of the game, "yoru no nai kuni" translates to). Now, several centuries later on a small island city known as Ruswal, a ritual is to take place to keep the Nightlord sealed away. To maintain the seal, a maiden and a knight to protect her is chosen to perform a certain ritual, overseen by the church known as the Curia. The chosen maiden is a young woman named Lilysse, who is very close friends (and I mean VERY close - you can imagine what I mean, I believe) with the Agent of the Curia assigned to protect her, Arnice (a.k.a. best girl to end all best girls).
And that's about as far as I can tell you without spoiling any major developments.
You play as the aforementioned Arnice. She commands friendly fiends known as Servans, who all have different abilities depending on what species they are. She starts out with three, but you can acquire more in the game to form up to three parties of four Servans each (additional parties must be unlocked via leveling up, though). The way it works is that you have a hub in the form of the Ende Hotel (subtle, ain't it?), from which you pick different parts of the town of Ruswal to explore at night. For each exploration, you have a time limit of 10 minutes initially (it might be 15, I'm not sure), which extends the stronger you get. The justification is that Arnice, being a half-demon, succumbs to her demonic side if she's exposed to the night for too long.
In the field, you kill fiends of all kinds (some of which drop items that can be used to summon new Servans) in a free-flowing action combat style not unlike the Warriors games. Your Servans will act mostly independently, but you can switch tactics on the fly to change their behavior and every Servan possesses a special action (basically a pretty powerful special attack - Alraune's, for example, heals the entire party to full) that you can make them do whenever you want.
Defeating fiends will net you Blue Blood (this game's EXP), which you can spend on levelling up and getting new abilities. Bosses of course will get you much more of the stuff.
There is also a plentiful amount of practically infinitely repeatable sidequests, which are divided into two categories: daytime quests, which have Arnice do some activities during the day to get points for learning new abilities (these are done automatically, all you get is a diary entry that shows what happens and Arnice' thoughts on it), and nighttime quests, which work more like traditional quests (go to a place, fetch an item, kill fiends, that kind of stuff).
Your goal in the game is to explore Ruswal and uncover the truth behind the Curia, the Nightlord, the ritual, and the Saints. You also meet with a colorful cast of characters such as the receptionist Simon, the skirt-chasing scoundrel Lloyd, his buddy and resident Mad Scientist Professor Alucard (who wants to hire Arnice as his "research assistant"), and of course the second best character in the game, after Arnice herself, the enigmatic masked pureblood demon (so called because she doesn't have any human blood like Arnice does) Christophorus (male name, but it's a female character), who is voiced by the wonderful Tomoyo Kurosawa, otherwise known as the Japanese voice of Sothis.
Phew, that got wall-of-text-y again. My apologies for that.