Neptune is bossy and fashionable, and doesn't care what others might think of her or how her own actions might affect others. Neptune typically behaves as she would like to, with little regard for others' approval. While she can be nice to those she cares about, her tone comes off as rather abrasive and sarcastic most of the time.

Neptune does genuinely care for her friends, however, her ways of showing it are somewhat unconventional, if not aggressive.