There are spoilers ahead.
A bunch of gods from multiple pantheons have lost their connection to human hearts, and this will lead to a catastrophe if not corrected.
To prevent the gods from escaping, Zeus seals their powers with shackles that take the form of various pieces of jewellery. Meanwhile Yui has a sword pendant that connects to the mission in some way.
Playing with the Harem Tropes
I don’t know about the original game, but the early portion of Kamigami no Asobi felt like they were parodying various reverse harem tropes.
There was certainly a sense of fun, and that the show was winking at the audience, that kept me watching the early Day in the Limelight episodes.
The opening certainly hints at this:
Please Grow a Spine and Whack These Idiots
It’s just as well that there’s that sense of fun as it made me overlook my growing irritation with Yui.
The first seven to eight episodes mainly deal with Yui connecting with one or more of the gods, and bringing them into the school or friendship in some way.
None of these episodes ever involved Yui whacking the idiotic gods over the head with even a practice sword. This is what I meant by the misleading name: Kusanagi is the equivalent of calling a character Excalibur in English (among other examples).
I’ve seen enough anime to have expectations of that name, and Yui just didn’t fit the picture at all at any point in the series.
That isn’t to say that Yui is entirely passive, but I would have liked her character to be at least a little more assertive.
Or be given a name more indicative of her role as the emotional centre of the group.
Loki is WHAT?
The main plotline revolves around Balder Hringhorni being both the god of light and destruction. Zeus is hoping that connecting Balder in particular to the human heart will defeat, or suppress, Balder’s aspect of destruction. No prizes for guessing what actually happens.
So, in this version at least, Balder, Thor Megingjard, and Loki Laevatein are extremely close friends, with a hint of Yaoi between Balder and Loki.
Indeed, for all that he’s a prankster, Loki ends up being one of the heroes of the piece.
Particularly once his true friendship for Balder inspires both Yui and the other gods to come to Loki’s aid.
The conclusion itself is pretty much The Power of Love, although The Power of Friendship might be a better description. The ending is entirely predictable, but well enough executed that I enjoyed myself whilst it was happening.
Kamigami no Asobi isn’t a great show, but it is fun to watch and mostly harmless. Such fanservice as exists is mostly directed at the female audience, which is something of a change. As reverse harems go it isn’t as clever as Ouran High School Host Club, but still worth watching once as light viewing.
There’s possible sequel bait with no real relationship established in this season, and the gods appearing on Earth after the finale. As I tweeted afterwards, this has the potential to make Yui’s life interesting…
 That much at least is a fairly accurate rendition of Greek mythology.
 More of a cute playful kitten than the judge of the dead…
 This is one of the places where Kamigami no Asobi’s interpretation of mythology veers into some strange places.
 Shirts are apparently optional for the gods once they get their powers back…