The story of the first season follows the adventures of Kazuto “Kirito” Kirigaya and Asuna Yuuki, two players who are trapped in the virtual world of “Sword Art Online” (SAO). They are tasked to clear all 100 Floors and defeat the final boss in order to be freed from the game. Three months after the death game, Kazuto discovers that Asuna is being held captive in “ALfheim Online” (ALO), a spiritual successor to SAO, where the players assume the roles of fairies. Kazuto enters the game and allies himself with his sister Suguha “Leafa” Kirigaya to rescue Asuna from captivity.
List of Sword Art Online episodes (5 February 2018, at 08:20. UTC). In Wikipedia: The Free Encyclopedia. Retrieved from https://en.wikipedia.org/wiki/List_of_Sword_Art_Online_episodes
Song list of "Sword Art Online"