Karma is the belief that one's actions influenced the outcome one's life. If the person does bad things, bad things will occur to that person. (Vice Versa with the good things.)
The theme of Karma is common in anime and manga franchises where the character's actions will either award the character or haunt/harm them in the end.
"If you hurt people, they'll hurt you back."
From Yoh Asakura in Shaman King Volume 21
It has to be a reciprocal effect when one character does good or bad.
He kills Redseb and Salerm's father, Dr. Munzer, when his gang rob Dr. Munzer. Three years later, Redseb and Salerm finds him and kill him along with his gang members. Chocolove works off his karma by having Gandala take his vision.
*This may not relate to the characters since the types of karma are hard to connect to real life.
This is the total amount of karma (actions) done in one's previous, past lives and the present.
This is when someone starts an action but never finish it.
It is cause by the person's free decisions in their present life. It is like picking a path in life but not knowing what will happen.
The sum of Karma in one's present life. Their karma will affect their future lives.