Yuki Mutou is Yugi Muto's mother. Sugoroku Mutou has described as being just like his wife and has cursed his son for marrying a girl just like his mother.
Yuki returned home from grocery shopping to find everyone worrily watching Sugoroku dusting the top shelves ... while hanging from the ceiling by one foot clamping onto a banister rail. As both she and Author weren’t surprised by the display Joey decided to go into the shop to see what was going on. Only to promptly be attacked by Solomon who mistook him for Seto. Which caused him to be berated by Yuki for throwing knives at people.
Yugi asked what Kaiba did to him to warrant such a reaction. So Solomon sat down and finally explained to Yugi that he was that he was apart of the Kuramitsu clan a galactic empire. The then went on to explain that the Seto he afraid of was actually the "Devil Princess of Jurai,". Afraid that Seto had set her sights on Yugi Solomon engaged him to Tea and Rebecca to prevent her from matching him up with anyone.
Yuki was livid both that her father in law had engaged her son without her consent as well as the fact that he was just now explaining this to her. After she calmed down Solomon released his disguise cloak and explained that his son was going to tell her when he returned with his mothers. There conversation was interrupted by Bastet coming to return the Millennium Puzzle to Yugi.