Mary H.K. Choi has never been particularly interested in having her books fit neatly into a category. After becoming a beloved voice in young adult fiction with bestselling novels like Emergency Contact, Permanent Record and Yolk, she’s making the leap into adult fiction with Pool House—though, as she puts it, “I don’t really strive for or aim toward taxonomy. I don’t worry about what shelf the book is going to live on. I just write the book tha…