According to the Supreme Public Prosecutors' Office, the number of spontaneous assaults surged fivefold from 10,810 cases in 2004 to 71,036 in 2014.

Korean society seems to be suffering from anger management problems amid a spate of assaults simply for looking at someone the wrong way or bumping into others in the street.

The victims are often women, children and senior citizens. In one high-profile case, a 30-year-old woman in Suwon assaulted an elderly in his 70s without good reason. The woman said she kicked and struck the man with her handbag because he looked at her in a funny way. She later explained that she had grown angry after her clothing shop went belly up.

Ki Kwang-do at Daegu University said, "Spontaneous assaults are despicable since they target the weak, but most offenders face simple assault charges and end up getting off with light penalties."

Experts point to intensifying competition in society that leads to frustration and anger.

"Koreans have been inclined to bottle up their feelings, and this lack of experience in controlling emotions or urges is manifesting itself in spontaneous assault," says Yee Jae-yeol at Seoul National University.

And Lee Woong-hyuk at Konkuk University said, "People who are obsessed with the twisted notion that they must defeat others to succeed are expressing even minor grievances through physical force against the weak."