"A Reason for Continuing to Exist…!!" (在り続ける理由!!, Aritsuzukeru Wake!!) is chapter 97 of the original Naruto manga.
Naruto and Shikamaru ask why Gaara would want to kill Lee, but Gaara has no particular reason. They point out that, being two-against-one, they have the advantage, but Gaara is unconcerned and promises to kill them too. Gaara explains that he contains a monster, his mother's life having been sacrificed at his birth to seal a demon within him and give him control over sand. In the years that followed Gaara's father tried to have him assassinated to repent for making him what he is, but Gaara killed all of his attackers. His life having been surrounded by death, he finds love by killing others. While similar, both having something sealed within them, Naruto realises that Gaara's tragic background has made him too dangerous for them to defeat. As Gaara prepares to attack, Guy arrives and forces Gaara to leave.