>First half of the ep was all 'wtf am I watching?' almost disappointing that jersey girl wasn't actually a fairy there to take boring girl on a magical fantasy adventure,
The point is it was Naru's own wish all along, projected into her perception. Hoping someone would carry her own wish was the reason she felt lacking in her life. This is why she made the decision to take up the mantle herself and affirmed her encounter with "the fairy". At first she was in denial of the truthful encounter, but in the end she affirmed and declared "yes, yes!" to the new unknown realm. The whole story starts from that point onwards, it's too obvious.
Shows like this started by asking "how can a boring mundane schoolgirl life like this be meaningful?" and then proceed from the point to experiment itself. With cuteness.
In case you forgot NNB started with "how can a backwater, desolate, and retarded countryside like this, so devoid of youthfulness and life, be meaningful?"