Atatchi Mimi is a member of Goha’s Top of Hexagon, the executive board at Goha Corp. Despite looking like an elementary student, Mimi is actually 37 years old. When in public, Mimi often gets confused for a child, and that upsets her. (And why does Mimi look like a child? I have no idea.)
The Goha Top of Hexagon look at a picture of Yuga in the Goha 7th newspaper and notice that he has a notebook that contains the secrets of Rush Duels and perhaps how to uninstall it, so they send Mimi to try and obtain the notebook. Mimi arrives at Goha 7th Elementary and joins Yuga’s class. Since she looks like a child, she fits in quite nicely. In an effort to make the new girl feel welcome, Yuga invites Mimi to his Road Research Lab where he shows her the notebook. (A little to trusting isn’t he?) Later that night, Mimi tries to steal the notebook, but Yuga and company were hiding out. Yuga says that if Mimi wanted his notebook, all she had to do was ask. (Definitely too trusting.) Mimi suspects this is a trap and wants Yuga to keep it. To settle their disputes, Mimi challenges Yuga to a Rush Duel. If Yuga wins, Mimi has to take the notebook, but if Mimi wins, Yuga has to keep it. (A little reverse, don’t you think.)
The duel begins.
Mimi summons Bubbly Elf, Kanan the Ganguro Swordsmistress, and Haircut LaMoon.

These monsters are all Rush Duel versions of original Yu-Gi-Oh! cards; namely Mystical Elf, Kanan the Swordsmistress, and LaMoon respectively.
Gakuto says, “I didn’t expect to see such legendary monsters that were once so famous.” So…is this somehow connected to the original Yu-Gi-Oh!?
Mimi activates a spell called All-Night Fever that switches all Aqua monsters on her side of the field to defense mode and then she gains 400 life points for each one. Mimi gains 1200 life points. Mimi sets one card and ends her turn.
Yuga summons two monsters and tributes them in order to summon Sevens Road Magician and activates his effect to raise its attack points to 3000. Then Yuga activates Piercing and applies it to Sevens Road. Yuga sets one card and enters his battle phase. Yuga attacks Mimi’s Ganguro monster with Sevens Road and destroys it. With 0 defense points, Mimi now has 2200 life points. Yuga ends his turn.
Mimi tributes her other two monsters in order to summon Dian Keto the Gold-digging Master. Now we know the answer to the age-old question, “What did Dian Keto the Cure Master look like 50 years ago?”
Mimi sends a card to her graveyard to use Dian Keto’s effect. Mimi gains 1000 life points (hey, just like the spell card!), but the effect also lets her summon Kanan and LaMoon back to the field (the Rush Duel versions, of course). Then Mimi activates the spell card 3K Bolt. If Mimi has 3 Aqua monsters on the field, she can lower the ATK of one of Yuga’s monsters to 0. She chooses Sevens Road Magician, then attacks and destroys with Dian Keto. Yuga now has 1500 life points left. Mimi’s other monsters also attack, but Yuga activates the trap Dark Liberation. By returning four Spellcasters back to his deck, Yuga can destroy all of his opponent’s monsters in attack position. (So basically Mirror Force with a cost.) Then Mimi ends her turn.
Yuga summons Magical Beast Wolfram and Stray Familiar and sacrifices them in order to summon Dian Keto back from her graveyard. Yuga returns two Spellcasters from his graveyard to his deck in order to activate the effect of his Lydacross monster. Yuga can special summon 2 level 5 or lower Spellcasters from his hand. Yuga summons Hydro Magician and Hilt the Noble Arms Bearer. Yuga activates the effect of Noble Arms Bearer that allows a Warrior type monster to increase their ATK by 600. Yuga chooses Lydacross and uses it to attack Dian Keto, thus winning the duel.

Since Yuga won, Mimi has to take the notebook. She takes it back to Goha Corp, but when they examine it, it is filled with drawings of robots. They can’t figure it out.