Rene Ai
Rene is a girl who is friends with Joe and Mike. She is portrayed as a tomboy, but has a sweet side, and cares much about her family who stayed behind on Mars. She becomes jealous and possessive about her relationship with Joe. She is the second of the group to operate a ninja robot; she pilots the Phoenix Thunderhawk and is almost as daring as Joe in combat.
Rene acts as a sister to Mike and tries to help him get to know Jade. A local boy, Kenji, has a crush on her, but she does not reciprocate, and she gets irritated whenever Joe teases her about him. Whenever Princess Romina hugs or flirts with Joe, Rene becomes upset and hurt. As a result, she regularly asks Joe how he feels about her. She even says that she loves him and just wants to be with him, even if he went to Ladorio. Eventually, Joe reciprocates her feelings.