This means that boys like girls very much and don't want each other to escape. This action has different meanings in different places. If it happens in a collective house like an apartment, it is an accident. If two people love each other, then this impact is a kiss of love.

The word "hitting the wall" is very popular in Japan. In Japanese cartoons, it is often seen that the hero pushes the heroine into the corner and then leans against the wall with one hand or both hands. At this time, moderate force will make a plop, which will make girls have nowhere to escape. This action can also narrow the distance between men and women, and girls can easily feel shy.