Nain works with many other scientists in a laboratory in Mei Queen Castle, on a remote island. When Trunks manages to correctly describe one of the functions of the equipment within the Bio-Warrior laboratory, she compliments him on his knowledge. After Goten and Trunks assume that Bio-Broly is defeated, a Culture Fluid fills the laboratory and claims the lives of many scientists. However, Nain is rescued by Krillin, though she ends up hugging on to him tightly causing him to blush perversely which causes Krillin's wife Android 18 to angrily pushes Nain and Krillin, though he manages to fly over to a nearby stairway. After fleeing Mei Queen Castle, she and one of her male colleagues are holding onto Krillin as he flies above the sea and watch as Goten tries to stop the culture fluid with a Kamehameha to no effect before Dr. Collie explains the Culture Fluid has become unstoppable due to absorbing Bio-Broly's cells, though they discover it hardens when exposed to seawater after Mr. Satan manages to escape by jumping into the ocean. Afterwards Krillin leaves her together with Android 18 and the other survivors, while he and the boys go off to stop the culture fluid by splashing it with sea water using a Multiple Kamehameha.
- Nain and Dr. Collie are both named after the Japanese word korinai (懲りない), meaning "stubborn". Their names, together with Hei and Men-Men, are a reference to the Jōji Abe novel Hei no Naka no Korinai Men-Men.