第 5 集: 桐人前往中央市，亞絲娜與結衣調查Rath與Kazuto住院之間的關聯。
2018年11月4日 播出
Kirito continues his journey to the central city in the Underworld, while Kazuto Kirigaya in the real world remains unconscious and hospitalized. At Kikuoka’s request, Kazuto is moved to a better-equipped hospital; but when Asuna and Suguha attempt to visit him, they are turned away and told that no visitors are allowed until he recovers. Suspicious, they speculate that Kazuto may be at Rath, his part-time workplace where they research the Soul Translator. Asuna and the group decide to split up to find out more about Rath; however, they are unable to discover Kazuto’s whereabouts… (Source: Aniplex USA)