Ayeka Masaki Jurai is the first princess of the royal family of the planet Jurai. She is the eldest daughter of Emperor Azusa Masaki Jurai and his second wife, Misaki, making her the older sister of Sasami. Her arrival on Earth is driven by a search for her missing half-brother, Yosho, who was also her fiancé. However, her quest leads her not to her brother but to a confrontation with the space pirate Ryoko, the being she believes responsible for his disappearance centuries ago. During the battle that follows, she crash-lands on Earth and discovers that a young man named Tenchi Masaki can wield Yosho's sword, a power only accessible to those of noble Juraian blood. With her ship, Ryu-Oh, damaged, she is forced to stay at the Masaki family shrine, where she becomes a permanent member of the household.

Ayeka’s personality is a study in contrasts, built upon a foundation of traditional aristocratic upbringing. She is typically portrayed as well-mannered, modest, and proper, carrying herself with a graceful and refined demeanor that reflects her royal status. This composed exterior, however, masks a fierce and protective nature, particularly when it comes to her younger sister Sasami or Tenchi. She can be extremely snobbish and vain, often boasting about her lineage and looks, especially during her frequent arguments with Ryoko. When her temper is roused, the shy and demure princess can become just as loud, aggressive, and violent as her rival, casting aside her dignified air in moments of explosive frustration. This duality stems from her youth; she was originally an outgoing and affectionate tomboy like her mother Misaki, but she idolized her father's first wife, Funaho, who was calm and elegant. To emulate Funaho and impress Yosho, who considered his mother the ideal woman, Ayeka altered her appearance and suppressed her natural boisterous personality to play the role of the perfect princess.

Her primary motivation throughout the series becomes winning Tenchi’s affection, which places her in a direct and long-standing rivalry with Ryoko. The conflict between the two is a central source of comedy and drama, stemming from their diametrically opposed personalities and backgrounds. Where Ryoko is blunt, open, and sexually forward, Ayeka is reserved, traditional, and more demure in her attempts to get closer to Tenchi. Their rivalry can fluctuate from petty bickering reminiscent of siblings to full-blown, destructive feuds. However, this animosity is often set aside when Tenchi or the rest of their found family is in genuine danger, revealing an underlying layer of mutual respect and a shared goal of protection. Ayeka’s relationship with Tenchi is initially complicated by his resemblance to Yosho, but her feelings for him grow genuinely as she witnesses his kindness and swordsmanship. This connection deepens significantly when she discovers that Tenchi's grandfather, Katsuhito, is actually the long-lost Yosho, who gives the pair his blessing. Over time, her combative relationship with Ryoko softens as they come to share a household and a common interest in Tenchi's wellbeing.

As a member of the Jurai royal family, Ayeka wields considerable power, though she is generally not as overwhelmingly powerful as Tenchi or Ryoko. Her abilities are often defensive in nature but formidable nonetheless. She can fly at high speeds, possesses superhuman strength, and can generate powerful energy barriers and force fields capable of containing opponents as strong as Ryoko or Kagato. For offense, she can discharge energy blasts and summon two guardians, Azaka and Kamidake, which can project electrical attacks and assist in capturing enemies. Her most significant asset is her bond with her Royal Treeship, Ryu-Oh. This living ship is capable of generating three Light Hawk Wings, one of the most powerful defensive forces in the universe, and Ayeka once bravely piloted the underdeveloped ship into battle against Ryoko as a teenager. After Ryu-Oh is destroyed, Ayeka receives a seed from the goddess-like entity Tsunami to grow a new tree, ensuring her connection to her royal heritage continues.