Lu Xiaoxi and Zhang Zifei are a couple who love and fight in equal measure—inseparable when things are good, ready to strangle each other when they argue. Lu Xiaoxi is a strong, bossy older-sister type, while Zhang Zifei is stubborn and refuses to be controlled, but neither ever holds a grudge overnight. As a relationship counselor, Lu Xiaoxi gives others spot-on advice for patching up their love lives, yet when it comes to her own, she's driven to the brink by Zhang Zifei's split-the-bill approach to romance. She believes love shouldn't be calculated so precisely, while he thinks being "rational" is the only way to avoid feeling indebted.