A book makes a surprisingly good spanking implement. I’ve been spanked with books myself, in fact; they’re often at hand, they’re easy to wield, they give a satisfyingly thuddy impact that makes a great warmup beating. Their subjects can add a little something to the headspace, too: it’s amusingly apposite to be beaten with a copy of Crime & Punishment, and it can be extra humiliating if the chosen tome is by an essayist whose opinions you loathe. 

In the backstage content released alongside Part I, Sai and Eve talk about how they’ve both been around and alongside books their whole lives. Books have been an important part of their careers; Sai really was a bookshop manager for a good while, and Eve has worked in several others. They’re both avid readers, and the books they collect as a couple mean a lot to them.