Perfect Ruin - Claudia Tan

Sienna Lane is a confident high school student whose lack of an internal filter gets her into a bit of trouble. After deciding to attend an underground circuit fight at the gym for MMA, Breaking Point, Sienna Lane finds herself mesmerized with the dangerous sport. And even more memorizing is the unrelenting and powerful champion of the night, Jax "Deadbeat" Deneris, who just so happens to spot Sienna out of the crowd.
After riling up and insulting another underground fighter backstage, Jax swoops in, and while Sienna is no one's damsel in distress, there is something about this cocky bad boy that she can't seem to shake. And when Sienna's whole world is turned upside down by the news of her parent's divorce, the last person she wants to lose is Jax. He's a bit rough around the edges, but he's the only one who seems to understand the anger and frustration she is feeling towards her family. But as their relationship grows and their worlds begin to revolve only around each...