Since childhood, Monica loved sweets and would constantly chew bubble gum and complain about food that wasn't sweet enough. Because Monica's family was poor, her mother used to make bread for her all the time. Monica initially disliked it, but grew to enjoy it after the recipe was changed into a sweet bread. To support her family, Monica dreams to become the #1 pâtissière to carry on her father's dream, eventually winning the 39th world championship. She continued to strive until Yuuichi Kirisaki approached her promised to make her the manager of her own branch if she entered and win the Monaco Cup.
She faces against Kai in the finals under the theme "Clothing", where bread is judged primarily on its appearance. She creates a sculpted candy flower to compete against his glazed fruit.
She dresses in a bikini (US-themed) in an attempt to unsettle Kai, but he meets her challenge by stripping down to his underpants as well. She defeated the latter who complimented her hands by saying they are beautiful despite the damage made upon baking.
Later, during Yakitate! 9/25, she fights alongside Suwabara both dressed as ninjas on the side of St. Pierre against Azuma's Pantasia team. It is heavily implied at this point that they are lovers, as she came to Japan to be with him and later revealed by Ken Matsushiro to be pregnant with Kai's first son. Actually a lie on both her and Ken's part as Suwabara was about to commit Seppuku after having failed. Suwabara thought she was pregnant after "just hugging".
- Kai Suwabara: The two were somewhat competitive with each other since their meeting at the Monaco Cup finals. But after the match as the two acknowledge each other's skills, Kai noticed Monica's scars and praised them as admiration for her hard work. Monica couldn't help but felt more than compliment in return where she began to have feelings for him. Kai did not reciprocate as it was sturdily against his honor until the Yakitate!! Game Show Arc, where the two team up for Kai's next chance to beat Azuma. After losing and ready to commit seppuku for betraying his friends, a lie on both her and Ken's part about Monica's "pregnancy" convinced Kai to stop.