Sango is a very pretty teenage taiji (youkai exterminator) who lives in the village of the Taijiya with her younger brother, Kohaku, and her father who is also the head of the village. This very village consists of powerful humans that have learned to master the techniques of youkai extermination and frequently helps others remove youkai from their villages.
Sango is skilled with two basic weapons, a katana, and her most noted weapon, the massive boomerang, Hiraikotsu, which is made of the bones of youkai that have been killed. She also uses assorted weapons such as gas bombs, hand-to-hand combat, and the help of her pet youkai, Kirara, who is a flying fire cat-like creature.
Being the daughter of the village leader, she learned the trade along with her father, who wanted nothing more than for Sango to live strongly in life. Sango was more than happy to take up the job. One day, the best taiji are called to a castle to help exterminate a spider youkai that appears every night to attack the castle.
Using powers of deception, the demon possesses Sango's younger brother, Kohaku, and causes the boy to kill his own father and all the rest of the taiji. Sango tries to stop him and realizes all too late that he's being controlled, and ends up getting hit in the back with Kohaku's scythe weapon. The guards of the castle think that Kohaku has gone insane and shoot him full of arrows, and then right before he dies, he comes back to his senses and cries to his sister who tries to crawl over to him. Thinking she's insane too, they shoot her full of arrows and she appears to die.
After being buried, Sango pulls herself through out of the ground and Naraku takes her in and cares for her. He then uses more deception against her and tells her sadly that her village was attacked by youkai and everyone was killed. Furious and nearly dead from pain, Sango asks who the person that did this was, and he tells her, "The hanyou, Inuyasha". Driven by her hatred for Inuyasha, she heads back to her village with Naraku's servant and nearly dies from the pain of trying to fulfill her last mission: kill Inuyasha. Baboon Naraku offers her a Shikon shard and tells her that he'll lend it to her so she can kill Inuyasha. She takes it and wears it in her back thus removing her pain. She's still bleeding heavily, but she can no longer feel pain.
She finds Inuyasha and attacks him, but Inuyasha convinces her that Naraku is the one who betrayed her, and she collapses after the Shikon shard falls out of her back. Kagome helps her recover, and she decides to join their group to seek revenge for the deaths of her family and entire village.
As she travels with the group, she and Miroku start to develop a relationship. She's the one who reveals the secret of the creation of the Shikon no Tama to the group, since her village is where the jewel itself originated from.