CHARACTERS HISTORY (taken from Wikipedia):

Katniss Everdeen:
Katniss Everdeen is the 16-year-old protagonist of the series. Normally quiet, she lives with her mother and her younger sister Primrose (often shortened to Prim) in District 12, one of the poorest districts of Panem, which is in charge of mining coal for the Capitol. Her looks are typical for someone from the Seam (the slums of District 12): long black hair, which she wears in a single braid down her back; olive skin; and gray eyes. Five years before Katniss became a tribute in The Hunger Games, her father was killed in a mining explosion, and her mother fell into depression. She does not start trusting her mother again until the events of Catching Fire. In order to provide for her family, Katniss began to hunt and pick plants in the woods, just as her father had taught her. In the process, she becomes hunting partners and best friends with Gale Hawthorne, who is also from the Seam and whose father was killed in the same mining accident as Katniss's.
When it comes time to draw the tributes for the 74th annual Hunger Games, Katniss' sister Prim's name is drawn, but Katniss volunteers to take her sister's place. When she is introduced to the Capitol along with the other tributes, her dress is "set on fire" by her stylist, Cinna. This gives her the nickname "the girl on fire", which is used recurrently during the trilogy. During the interviews which precede the Games, Peeta expresses his love for her on live television, which Katniss assumes is a ploy to gain attention from wealthy sponsors. Later, as they grow closer to each other, it appears that his love is genuine, though she is uncertain about her own feelings. Halfway through the Games, a new rule is instituted allowing both tributes from a District to become victors, causing Peeta and Katniss to form an alliance. However, when only Peeta and Katniss are left, the rule is reversed, in an attempt to force one of them to kill the other, which will ensure a more dramatic ending. At that time, Katniss decides that both of them should eat poisonous berries called nightlock, killing themselves and ensuring the Hunger Games have no winner. This is seen by the audience as an act of undying love. As a result, Seneca Crane hastily ends the Games, and both Katniss and Peeta are declared winners, humiliating the Capitol. This choice makes Katniss a symbol of rebellion for all of the Districts.
In the second book, Catching Fire, Katniss becomes aware of her conflicting feelings for both Gale and Peeta. It is revealed that her and Peeta's act of "undying love" that helped them win the previous games was seen as an act of rebellion by the Capitol. Peeta and Katniss compete with each other in the Third Quarter Quell, or the 75th Hunger Games, in which Katniss and several other tributes escape from the arena, while Peeta is captured by the Capitol. Katniss is taken by the rebels to District 13.
In Mockingjay, Katniss helps to end the war, but her sister is killed, Katniss is left burned in a bombing near the President's mansion, believed to be set off by the Capitol, right before the end of the war. After a talk with President Snow, she realizes that it was President Coin of District 13 and the new president of Panem, who ordered the bombing. Instead of executing President Snow, as had been decided, she kills Coin to avenge Prim's death and prevent someone as brutal as Snow taking his place. After being exonerated for Coin's death, Katniss is sent back to District 12. In the epilogue, set fifteen years after the end of the story, it is implied that she has married Peeta, and they have two children, one girl and one boy. In Catching Fire, It is said that her favorite color is green.
Collins has said that Katniss "is a futuristic Theseus."

Johanna Mason:
Sarcastic and mean-spirited, Johanna's first meeting with Katniss involves her stripping out of her tree costume in order to make Katniss uncomfortable. She reveals that she has no friends or family in District 7 during the 75th Hunger Games, stating "there is no one left I love." She won her original Hunger Games by pretending she was a weakling and a coward, so no one regarded her as a threat, but when only a few tributes remained, she revealed herself as a vicious killer. Johanna teams up with Katniss, Peeta, and Finnick in the Quarter Quell, bringing Beetee and Wiress with her. Katniss describes her presence as being akin to having an older sister who hates you. Johanna takes part in the committee to keep Katniss and Peeta alive, and helps by protecting Katniss throughout the Games. Near the end of Catching Fire she removes the tracker in Katniss' arm by cutting it out with a knife. Johanna is captured by the Capitol at the end of Catching Fire. In the third book, she is rescued along with Peeta and Annie and brought to District 13, where she fights with rebel forces and improves her friendship with Katniss. She is to fight in the Capitol with Katniss (although not as a sharpshooter — being from an area where lumber is the main export, her main weapon is the axe) but during training in District 13 she panics when the training arena is deliberately flooded. Katniss later learns Johanna has a fear of water, which developed as a result of her Capitol torture: being soaked in water and given electric shocks. Because she and Katniss refuse to be held in the District 13 hospital to treat their supposed mental illnesses, they convince the officials of District 13 to let them room together. Johanna is part of the committee that votes whether or not to hold one last Hunger Games using the Capitol's children: she votes yes.

my favourite

But my second favourite is Johanna :D.

I love Johanna too, but Katniss is my overall favourite so I had to pick her <3

Katniss is my favorite, but I love Johanna too.

She's my favorite in the entire series!