What is the Meaning of Patting Someone’s Head ?
In Japan, it is common to pat small children’s heads to praise them for being a good boy/girl. This is generally done from parents to their children, from relatives to children, or from older brothers/sisters to younger brothers/sisters. Patting someone’s head shows that there is a bond of trust between them.
If you look at Tina Sprout (left girl) and Rentarou Satomi (right boy) in this image from “Black Bullet”, you can see that they already have built trust between themselves, although they were hostile towards each other in the past. Even though Tina is a child, she would behave unpleasantly or would even refuse to interact with Rentarou if she didn’t trust him.
However, in the rebellious period he / she will refuse to be stroked their head by the parent like this image from “Tokyo Magnitude 8.0”. They insist that “I am not a child.” But for parents, child are a child. Parents stroke their child’s head, thinking “You are a good girl, try hard to study.” It is a scenery of everyday life that is often seen in Japan.