Names：

Yellow Four

（Mika Koizumi）（Jun Yabuki）
Status： Yellow Warrior of Choudenshi Bioman
Tags： Yellow WarriorFemaleChoudenshi Bioman
Affiliation： Choudenshi Bioman
Inherit： Dyna YellowYellow Flash
World： the World of Super Sentai
LeveL： B

During the first assault by Neo Empire Gear on Technotopia 21, she was caught in the crossfire and ran into Bio Robo. Meeting Peebo, she was given a Techno Brace and became Yellow4. She shortly quit the team and walked off. The other Biomen eventually convinced her to join them, and she became a Bioman for good.

Ultimately, Mika heroically took it upon herself to give her life to save her teammates, and sustained several repetitive blasts of Anti-Bio Particles from the Bio Killer Gun wielded by Mason. Following the complete depletion of her Bio Particles, Mika was then hit with powerful attacks from Psygorn, resulting in her death. The team later gave her a proper funeral while still in her Yellow4 form.

The others were looking for another descendant of the original five who were bombarded with the Bio Particles. However, Jun proves her courage, and it was also a pleasant surprise to discover that she has Bio Particles. It was thus with great joy that she was presented with a Techno Brace to become the new Yellow4. She has to sacrifice her membership in the Japanese Olympic Archery Team, yet her skills become valuable to the Biomen.

During the first assault by Neo Empire Gear on Technotopia 21, she was caught in the crossfire and ran into Bio Robo. Meeting Peebo, she was given a Techno Brace and became Yellow4. She shortly quit the team and walked off. The other Biomen eventually convinced her to join them, and she became a Bioman for good.

Ultimately, Mika heroically took it upon herself to give her life to save her teammates, and sustained several repetitive blasts of Anti-Bio Particles from the Bio Killer Gun wielded by Mason. Following the complete depletion of her Bio Particles, Mika was then hit with powerful attacks from Psygorn, resulting in her death. The team later gave her a proper funeral while still in her Yellow4 form.

The others were looking for another descendant of the original five who were bombarded with the Bio Particles. However, Jun proves her courage, and it was also a pleasant surprise to discover that she has Bio Particles. It was thus with great joy that she was presented with a Techno Brace to become the new Yellow4. She has to sacrifice her membership in the Japanese Olympic Archery Team, yet her skills become valuable to the Biomen.