Dr. Hoshi is the principal of Academia and one of the key figures behind the Liveman project. He created the Gran Tortoise and gave the team's mecha the ability to combine, ensuring the surviving Academia students would have the power needed to fight Volt.

During Volt's attack on Academia Island, he died while helping a pregnant woman escape from the rubble. His sacrifice became part of the tragedy that pushed the Livemen into battle.

Colon is a female robot built by Dr. Hoshi to manage the Gran Tortoise and assist the Liveman team. She provides technical support, field assistance, and direct backup during missions, often helping before Black Bison and Green Sai join the team.

Although mechanical, Colon shows strong emotion and loyalty. She becomes involved in several personal stories, including her bond with the Dummyman Tanaka and her devotion to Yuusuke after saving him from a sword attack.

Takuji Yano was an Academia student who researched powered suits for space travel alongside Yuusuke, Jou, Megumi, and Mari. His prototype suit used a swallow motif, and he was Yuusuke's closest friend.

He was killed by Kenji Tsukigata while protecting his friends. His death devastated Yuusuke and later inspired his younger brothers, Tetsuya and Takeshi, through the unfinished promise of building a dream car together.

Mari Aikawa was an Academia student and the older sister of Junichi Aikawa. She worked with Yuusuke, Jou, Megumi, and Takuji on powered suit research, and her own design featured a dog motif.

Before her death, Mari was also involved in plans connected to the Bison Liner and Rhino Fire. Her murder at Volt's hands became one of the central wounds that later brought Junichi into the fight.

Doctor Dorothee is the leader of the Academia group that helped build the Bison Liner and Rhino Fire. She serves as a benefactor to Tetsuya and Junichi and later returns to assist the Livemen with a new power core for the Bison Liner.

Takeshi Yano is the youngest brother of Takuji and Tetsuya. Before Takuji's death, he dreamed of building a special car with his older brother.

After that dream is shattered, Yuusuke agrees to help Takeshi complete it. Their work leads to the creation of the Live Cougar, turning Takuji's unfinished promise into a weapon for the team.

Toshiko Omura is Go Omura's mother. When Go was young, she pressured him to succeed academically, leaving him with little room for a normal childhood and contributing to the insecurity that Bias later exploited.

When Go returns home while struggling with his transformation into Obler, Toshiko is horrified by what he has become. With Yuusuke's help, she reaches him through the motherly love he once knew and helps restore his humanity.

Yoichiro Misaki is Megumi's father and a master of the Higo Cross archery style. He travels to Tokyo intending to arrange a marriage partner for his daughter, but becomes involved in the conflict with Volt.

Although his own archery skills have faded with age, he is still perceptive enough to see through Volt's disguises. After witnessing Megumi use the Dolphin Arrow, he gains a new respect for the woman and warrior she has become.

Mai Funachi is a longtime friend of Yuusuke who works at a kindergarten. She also knew Kenji Tsukigata before he became Doctor Kemp.

As a student, she received special roses from Kenji that helped her mother recover from illness. She later donated rare blood to save Kenji after a laboratory accident, making her important to Kemp's later experiments. Her discovery that Kenji has become Kemp forces her to confront the tragedy of what Volt has done to him.