Before heading to Yorknew City, Gon and Killua had once returned to Whale Island together. There, Killua experienced a delightfully heartwarming "meeting the family" ritual.
To put it simply, Gon introduced Killua to Aunt Mito, who was as kind as a mother to him, as well as his gentle great-grandmother. At the same time, Mito handed Gon a cassette tape left behind by Ging. This recording revealed Ging's whereabouts and destination, and once the message was delivered, the tape automatically destroyed itself.
At that very moment, the two little fellows finally found their direction forward: Greed Island.
Chapter 224