Abril Aguila is a central member of the Star Sheriffs and serves as the second-in-command of the team, which is led by Saber Rider. Her full name appears as both Abril Aguila and April Eagle depending on the translation. She is a young woman with fair skin, long blonde hair, and blue eyes, often seen wearing a red headband and a distinctive pink and white uniform when on duty as a Star Sheriff.

Abril's most defining characteristic is her extraordinary intellect. She is portrayed as a genius-level engineer and scientist, responsible for the design of the team's primary asset, the massive transformable spaceship known as the Ramrod, or Ariete. Her technical expertise is not merely supportive; she is the architect of the team's most powerful weapon against their enemies, the Vapor Beings or Outriders, and was in charge of the entire Ramrod Equalizer Unit project for the Cavalry Command.

Beyond her technical genius, Abril is characterized by her bravery and strong moral compass. She is deeply compassionate and has a notable aversion to violence, being repulsed by the thought of taking a life, even that of their adversaries, the Outriders. This pacifistic trait adds a layer of moral complexity to her role in a combat-focused team. Her primary motivation is to protect the New Frontier and maintain peace, using her scientific abilities to counter the technological threats posed by the Vapor Beings who invade from another dimension.

In the story, Abril is not only the team's engineer but also a key field operative who patrols space alongside her colleagues. Her role is essential, as the Star Sheriffs are technologically inferior to their enemies and rely on the Ramrod, her creation, to level the playing field in combat.

Regarding her key relationships, Abril is the center of several romantic subplots. She initially harbors romantic feelings for the team leader, Saber Rider, but he remains oblivious to her affections. Consequently, she later becomes the girlfriend of another teammate, Fireball. This romantic storyline is a recurring element of her character development throughout the series. Her working relationship with Saber Rider predates the formation of the Star Sheriffs, as she was already working on the Ramrod construction project before they were joined by other members like Fireball and Colt.

Abril undergoes significant development as the series progresses towards its conclusion. In the final battle, she uncovers a crucial truth about the main antagonist, Nemesis, learning that he was forced to transfer his mind into a powerful computer after being mortally wounded years earlier. This revelation contributes to the resolution of the central conflict, culminating in Abril and her comrades being banished to the Vapor Zone alongside the Outriders, effectively ending the threat to the human dimension.

Her notable abilities extend beyond her engineering prowess. While her primary function is technical and strategic, she is a fully-fledged member of the Star Sheriffs, capable of piloting vehicles and participating in missions. However, her unique value lies in her scientific mind, which is presented as the team's greatest asset in understanding and combating the advanced technology of their extradimensional foes.