Chara is the first person who gets the Underground in the Undertale. In fact, when the player names a character at the beginning of the game, he chooses not a name for Frisk, who is the main protagonist of the game for whom the player will play, but for the first person who fell to the monsters. For them, she became a kind of symbol of hope that someday they, people and monsters, will be able to live together again in peace.
After she ended up in the Underground, she was taken in by the royal family. For Toriel and Asgore, she became like their own daughter. She quickly became friends with their son, Asriel, with whom they spent a lot of time together.
Unfortunately, her life ended quite early and tragically, as she first became very ill and later died. Not long before she died, she asked to see the flowers that grew in her home village, but she could not live up to this moment. Therefore, later Asriel absorbed her soul and went to her homeland, passing through the barrier.
As a result in Undertale, upon seeing the monster, people mistakenly thought that he caused the death of the child, so they began to attack him. Due to a large number of injuries, Asriel soon died. It also was shown in the game.
Passing the game, the player can learn many details about the friendship between man and monster. All this can be learned from dialogues and cassettes. There is also an opportunity to play for Asriel’s friend at the very end of the Genocide path in the game when she will be given the choice to destroy the world or not, but in the end, whatever the player chooses, there will be one outcome in Undertale.