It is said on the Internet that women are like wolves in their thirties and tigers in their forties. Men, on the other hand, go downhill after their thirties. 
That is why, a young man paired with an older woman is the perfect combination. 
Guo Zhi, woman, 28 years old, has a car and a house. 
Alex, man, 20 years old, has no fixed place to live. 
What Alex worries about is how he can rely on Guo Zhi for all his life.