The Flower of Evil (Hangul:악의 꽃) is a manhwa by Lee Hyeon-Sook.

In the public eye, Se-wa is an ice princess that cares only for her brother, to an obsessive extent.

Se-joon and Se-wa meet a boy who introduces himself as an old friend, Sung-chan, who has changed his name to Gi-hoon.

During a class reunion, Se-joon meets the real Sung-chan who resembles Gi-hoon but is clearly not the same person who has befriended Se-wa.

Se-wa's struggle for life or death caused Se-joon to realize what she means to him, and his possessiveness became dark and deep.

He confronts Se-joon, who clubs him on the head and leaves him for dead, although Gi-hoon was brought to the hospital by a witness to the attack.

Thinking he has murdered Gi-hoon, Se-joon flees with Se-wa to their grandmother's house in the country.

His mother goes in to call him out to dinner only to find that he had slit his right wrist and in the other he carries a picture of him and Se-wa laughing happily together.

When the rumors started circulating about a purported incest betwin twins in school, See-Joon rejected her advances and takes on a girlfriend.

Gi-hoon's ex-girlfriend who hurt Se-wa; she lost an eye when Se-joon attacked her in defense of his twin.