Cullen plays by her own rules, and only does what she wants, wandering around alone quite often. Her number one interest is music, and she is always in search of songs she likes. She sometimes chooses to sleep in a tent inside the ship rather than in the residential area, although this may be to listen to her music in peace and without crewmates asking she turn down the volume. Cullen is one of the five main operators of the Vital Guarder, and the current girlfriend of fellow lone-wolf and VG pilot Yuki Aiba.