Jenny Ai, occasionally referenced as Renny or Lennie Ai, is a 16-year-old human girl living on Mars during the 23rd century. She forms a close trio with Joe Maya and Mike Coil, regularly participating in their illegal rabbit hunts using firearms. Her personality combines no-nonsense practicality, fierce determination, stubborn resolve, and profound devotion to her family, who endure persecution under Mars’ tyrannical ruler, Commander Hazzard Pascha.

Following the crash of the alien vessel Xenos 5, Jenny is captured alongside Joe and Mike. She becomes the second of the group to pilot a ninja robot, commanding the Phoenix Thunderhawk. In battle, she matches Joe’s audacity, repeatedly saving him from peril. Her driving motivations include shielding her family from Hazzard’s machinations and aiding the Xenos 5 crew.

Jenny harbors intense, unreciprocated feelings for Joe Maya. She reacts with visible jealousy and possessiveness when he engages with Princess Rowena or flirts, sometimes escalating to violent outbursts over his perceived indifference. Despite this friction, Princess Rowena confides her own affection for Joe to Jenny, forging a temporary truce where both prioritize their mission to liberate Ladorio.

Her bond with Mike Coil is supportive and trusting; she counsels him on wooing Jade from the Xenos 5 crew. Jenny openly challenges Joe about his behavior toward her, with Mike occasionally stepping in to defuse tensions. When a local boy named Kenji develops a crush on her, she dismisses his advances and grows irritated by Joe’s teasing about it.

Initially resistant to traveling to Ladorio for fear Joe would choose Rowena, Jenny commits fully after Joe declares his love in the final episodes. This resolves her core emotional struggle. Across the series, she evolves from a teenager preoccupied with personal stakes into a resolute warrior engaged in galaxy-wide conflicts.