U-Ikasaman was a Daimon created by Mimete. Her creation also caused a dimensional rift in the Tomoe household, something not anticipated by Mimete. She was not assigned to steal anyone's Pure Heart Crystal, but instead gambled with the Sailor Senshi.
When Professor Tomoe left the lab after showing Mimete the next time to be used in the Daimon Oven, Mimete crammed as many game related objects into it, in hopes of making a better Daimon. This, however, caused the oven to overload and created U-Ikasaman, who trapped the Tomoe residence, connected to the lab, in a warped dimension with Chibiusa and Hotaru still inside the house. The Sailor Senshi teleported in and confronted U-Ikasaman, who told them she'd let them leave if they beat her at a game. Sailor Jupiter picked roulette, and would have won, except U-Ikasaman changed the number and trapped Sailor Jupiter. She beat Sailor Mars at Jenga by attaching a Jenga piece to a string to make it fall over, and beat Sailor Mercury at chess by blowing up one of her chess pieces. Sailor Moon and Sailor Venus raced her in an arcade racing game together, but she controlled their cars to make them collide.
It seemed like they would remain trapped forever when Chibiusa and Hotaru challenged her to a game of cards. U-Ikasaman was unable to cheat at this one, and underestimated Chibiusa and lost. She challenged Hotaru to a 1 on 1 card game, in which she'd win if she picked the ace of hearts, but lose if she picked the joker. Hotaru was able to ignore U-Ikasaman's words of trickery and, as she had done many times before, pick the ace of hearts. U-Ikasaman was a sore loser and tried to keep them trapped. Chibiusa transformed into Sailor Chibi Moon (unseen by Hotaru) and used Pink Sugar Heart Attack to set Sailor Moon free. Sailor Moon then transformed into Super Sailor Moon and destroyed U-Ikasaman with Rainbow Moon Heart Ache, freeing the house from the dimensional rift.
U-Ikasaman had the power to control the dimensional rift in the house, and even claimed that she could send the Sailor Senshi into another dimension if they did not play her games with her. She also used her powers to cheat the Sailor Senshi into losing.
- U-Ikasaman is among the Daimons that appear in Sailor Moon: Another Story.