Megumi is the younger sister of Haruka and a trainee in TERRA's command centre. Though at first she is annoyed not only by the presence of Ayato, but also by the fact she has to hang around him a lot, she eventually grows to love him. In the beginning, she is attracted to her superior officer, Major Yagumo, but she moves on to Ayato when she learns that her best friend, Kim, is dating him. She also "renounces" her love of Ayato in the last episode for her sister's sake.

Megumi is easily annoyed by Ayato to the point where her facial expressions become somewhat atypical of a drama like RahXephon.