A Tale for the Time Being by Ruth Ozeki. MY GOD.

Dual narrative. One part - Nao, a Japanese school girl - had a really interesting narrative; the other, a Canadian author called Ruth (really? she had to name the character after herself?) found Nao's diary washed up and was reading it, in between doing all sorts of dreadfully tedious things with her dull, dull partner.

The ending launched into some weird metaphysical dream sequence, and then Nao's section abruptly stopped. It was obvious why, but the fact that I'd wasted so much of my time slogging through the monumentally monotonous 'Ruth' sections to then have zero closure with the 'Nao' sections made me want to hurl it across the room. I was in a cafe when I finished this book so alas could not, but rather swiftly donated it to a second-hand bookshop.