One of the more enthusiastic members of the Sci-Fi Club, Natsuki seemed eager to take it upon herself to see that Tetsuro's work was turned in on time. She had a semi-close frienship with Tetsuro, but didn't seem to know Sho very well, if at all.
After Chronos had taken control of the world, Natsuki took it upon herself to act as the caretaker to the survivors of the Mt. Minakami debacle: Tetsuro, Mizuki, Yohei, and Shizu. It was also later stated that she is a Christian.