This article is about a/an ally in Choudenshi Bioman.

Yellow4's Ancestor is a normal human who lived 500 years in the past who was exposed to Bio Particles after an encounter with Bio Robo. She is the ancestor of Mika Koizumi and Jun Yabuki, both of whom ultimately becomes Yellow4 in modern times.

Character History

She was one of five humans who initially heard the arrival of Bio Robo to Earth after it arrived on the planet escaping planet Bio's destruction. Upon seeing the giant robot, she is granted Bio Particles by the machine, thus giving her the power of Bio and the ability to use its powers and abilities; ultimately allowing her and all of her descendants to become a member of Bioman should the need be required.


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Behind the Scenes

  • Because of the sudden departure of Mika Koizumi and her replacement by Jun Yabuki, it can be reasoned that both are descendants of the woman who was struck by Bio Particles and thus gained the line to become Yellow4, despite the fact that Yuki Yajima (who portrayed Mika) portrayed the ancestor.
    • This element is furthered by a later episode where this scene is reaired and it shows four of the five Bioman from the initial episode after which, but then shows a later shot of Jun after she awakens to her Bio Particle potential.


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