I'm a librarian who loves anime, manga, and reading a wide variety of genres.
... I want to say, "Are you serious?" Because almost everything I've read so far has been angst. There's the breakup scene at the start, sure, but then there's also Alice's intense stress and anxiety about her identity and what she wants out of a relationship after she meets Takumi. And I'm still only a third of the way through the book.
One of those times I kind of wish I had a Twitter account. Thankfully someone jumped in and mentioned some of this stuff, because otherwise I'd worry more about the folks who'd go into this book expecting something light and fluffy (sort of like I did - that'll teach me to believe random squeeing book bloggers).