One example is men's complaint that if they offer solutions to problems that women bring up in conversation, the women are not necessarily interested in solving those problems, but mainly want to talk about them.
The book states that most common relationship problems between men and women are a result of fundamental psychological differences between the sexes, which the author exemplifies by means of its eponymous metaphor: that men and women are from distinct planets—men from Mars and women from Venus—and that each sex is acclimated to its own planet's society and customs, but not to those of the other.
On the plane ride back from a quick business trip to the United States, Joo Eun has an embarrassing run-in with Kim Yeong Ho (So Ji Sub) and his two sidekicks, Jang Joon Seong (Sung Hoon) and Kim Ji Woong (Henry Lau).
Yeong Ho is a celebrity personal trainer who is involved in a scandal in the United States and forced to flee to Korea until things cool down. As soon as they discover that he is back in Korea, his grandmother appoints Yeong Ho as the new president of the family medical services company and prevents him from returning to the States.
This is a time when only communication can help to bring the relationship back into balance.
Gray further asserts men and women view giving and receiving love differently, how individual actions intended as loving expressions are "tallied up." According to Gray, women and men are often surprised to find their partners "keep score" at all, or that their scoring methods differ widely.
A lost purse causes Young Ho to reconnect with Joo Eun and witness another personal embarrassment for Joo Eun in the aftermath of being dumped by Woo Sik and finding out that he has been dating her new boss, Oh Soo Jin (Yoo In Young).