After the death of their father, 11-year-old Shion was gifted a strange band. With the band came a mysterious presence whispering in their ears that would give them helpful advice in challenging situations. 5 years later, Shion and the spirit (now called Ghost by the teen) worked together to become highly ranked in Duel Monsters tournaments throughout the country. When invited to Pegasus' Duelist Kingdom tournament, Shion remembers the man working closely with their father (and was the one who originally gave Shion's family the band). Shion suspects Pegasus had something to do with his death. Shion and Ghost accept the invitation, planning to win the tournament and question Pegasus about Shion's father and why he gave them the Millennium Band in the first place.
5 parts