Romi, also known as Princess Romy, began life as an orphan in India. She married an Indian Rajah, a devotee of the goddess Kali. After his death, she faced the ritual of suttee, destined for immolation on his funeral pyre. Rigodon intervened and rescued her, marking her introduction to the group.

Her initial motivation for joining Willy Fog's journey was to locate relatives in Singapore. Discovering they had perished, she chose to remain with the traveling party indefinitely. Throughout the global expedition, she served as the group's medic, tending to the wounded they encountered.

Her relationship with Willy Fog evolved significantly during the journey. She developed deep admiration for his gentlemanly conduct and noble character. When the group returned to London believing they had lost the wager, leaving Fog financially ruined, she proposed marriage to share his burdens, which Fog accepted. Her proposal coincided with Rigodon's realization that crossing time zones eastward had gained them a day, allowing Fog to win the wager.

Following their success, she offered to dissolve the engagement, considering its original purpose fulfilled. Fog, having developed genuine affection and gratitude towards her, declined. They proceeded with their marriage plans.

Romi consistently demonstrated compassion through her medical role and perceptiveness, notably identifying the time zone miscalculation that nearly cost Fog the wager. Her character is depicted as a blue-grey feline panther.