As Naruto explains, Sasuke left because he wanted to gain power. The Uchiha Clan was annihilated, and he's been wanting to get revenge as the sole survivor. But Boruto's confused at this, so Naruto explains that Sasuke did it in order to sever all his bonds.
Episode 109: An Invitation from the Sound is the beginning of Sasuke leaving the Leaf Village and goes all the way to Episode 134: The End of Tears in the Naruto Series.
Sasuke leaves Konoha and joins the Sound Four. Sasuke went to leave the village that night, but was disrupted by Sakura, who then tried to convince him to not leave Konoha. During this conversation, a crying and desperate Sakura confessed her love to Sasuke, and begged him not to leave the village, but he rejected her.
smell bad. nuka (also: kunuka) stink.
Kyōko, Kyoko, Kyouko or Kyohko (きょうこ, キョウコ, 京子) is a very common feminine Japanese given name. Not to be confused with Kiyoko.