I totally get why you'd want more books like 'Rival'—it’s one of those stories that sticks with you, right? If you loved the intense rivalry and emotional depth, you might enjoy 'The Song of Achilles'. It’s got that same blend of personal conflict and heart-wrenching bonds, though it’s set in ancient Greece. The way Madeline Miller writes about competition and love is just chef’s kiss. Another pick could be 'Red, White & Royal Blue', which swaps out mythological stakes for political ones but keeps that delicious tension between rivals-turned-lovers. The banter is top-tier, and it’s got the same addictive quality where you can’t put it down.
For something grittier, 'Six of Crows' has rivalries that are more about survival than romance, but the dynamic between Kaz and Jesper has that same electric back-and-forth. Leigh Bardugo really knows how to make you root for characters even when they’re at each other’s throats. And if you’re into manga, 'Blue Flag' explores rivalry in a quieter, more introspective way—it’s like someone bottled up all the bittersweetness of teenage friendships and poured it onto the page.