Moena Wakakusa is a student and member of the Tokyo Branch of the Earth Defense Force's HxEros team. She possesses yellow/blonde hair, green eyes, and consistently sports a mask over her mouth. This mask supports her heightened sense of smell, a critical ability for detecting Kiseichū alien threats. She operates closely as Shiko Murasame's silent partner within the team, which also includes Tōma Taiga and Yona Ichōgi in their mission to combat the Kiseichū invasion.

She shares a past connection with Saitama Branch member Momoka Momozono, having attended the same middle school. Moena expresses affection for Momoka through the nickname "Momocchi". For combat, Moena utilizes an XEro gear device concealed within one of the ribbons securing her pigtails, essential for HxEros operations. Her acute olfactory sense serves as a key tactical asset for identifying enemies.