The knot is a hacking puzzle[1].
Involvement[]
In 2050, on b0nb0n's birthday, the mini disc on which the knot is stored arrives gift-wrapped at the door of b0nb0n's apartment without a return address[1]. b0nb0n immediately goes to work[2]. After devoting considerable time and energy to the project, b0nb0n finally solves the knot after her return from Tokyo, earning an invitation to The Children of Kobayashi[3].