|This article is about a/an episode in Choudenshi Bioman.|
Prince's Challenge! (プリンスの挑戦！ Purinsu no Chōsen!) is the twentieth episode of Choudenshi Bioman. This is the conclusion of the two-part story involving Bioman dealing with Doctor Man's son, Prince.
In the Philippine Dub, the title of the episode changed to "A Fight to the Finish!".
As the Bioman try to figure out how to deal with Prince and his Grotes Canth, Ryuta tries to discover how to relate his own experiences in hopes of dealing with Doctor Man's son.
The episode continues after Episode 19 where the Prince pilots the Grotes Canth against the Bio Robo piloted by the Bio Team. Doctor Man was impressed with his courage as he coughs and maniacally laughs while watching the Bio Team suffer. However, The Bio Robo manages to expose the wires as it cut off which the Prince provokes that it was temporary as he escapes his mecha to destroy once and for all.
During his escape, he along with his mechaclones shooting every mothers and chlldren while riding the jeep which Peebo alerts the Bio Team while inside the Bio Robo who handling the wires that he took from the Grotes Canth about a group of mothers were attacked by the Prince and many were reported killed which they became horribly surprised by the news and Blue3 states that this is the last straw as he angrily gets off to save them. When both a mother and the children were cornered by the Prince and the mechaclones, he incapacitates the mother of a kid by shooting her in the left shoulder only to be thrown a rock by Ryuta who is now protecting them both which Prince was impressed to see him again. Ryuta points to him that the Bio Robo gave the wires back to Grotes Canth as he goes to rescue both a mother and a kid. Prince becomes intimidated by this as he orders one of the mechaclones to shoot them as it manages to grazed Ryuta's left arm and he angrily mad for his treachery as he kills the weak and the harmless even him or babies. He furiously challenges the Prince for being a shameless coward. When Shirou and the group arrive and to watch the confrontation between both Ryuta and the Prince, he angrily taunts him about how is going to happen when their children losing their mothers that he killed and who's gonna take care of them with their love when they were orphans. Ryuta calls him a murderer and someday his mother will die and to feel anguish of becoming an orphan. This impacts on the Prince's brain having remember who his mother is as he quickly left to find his mother. Shirou and the group arrive to help an injured Ryuta and Shingo tells him that his angry words had struck on the Prince's coordinates. Shirou realizes it was a key to their victory which they decide to follow him as they agreed.
Doctor Man discovers the Prince inhibits his human emotions where he was looking for his real mother as the latter scare the woman with her child away. He becomes infuriated due to Ryuta's angry words, he sent both Farrah and Mason to capture him. By the time the Prince continues to scare the girls away while looking for his real mother, he simply attacked a girl with his mecha's wire in tow. Prince simply mistakes the girl as his mother as the woman turns out to be Farrah in disguise. He is later confronted by Mason from behind along with Zygorn as Shirou and the group hides to see the turn of the events. When Mason orders Zygorn to hit him with a telekinetic ray, Prince retaliates by shoots his electronic zapper as they clash with their zappers. Both are later electrocuted and to discover the Prince is in fact a mechaclone which is a shock to both Farrah, Mason and Shirou's group. However, Doctor Man saw this in the monitor from his base as he leaves. Both Farrah and Mason are confronted by Shirou and the group and they finally take the Prince as they teleported away.
At the Bio Base, Peebo finally realizes that the Prince is a mechaclone and Ryuta was bothered to think of the Prince as a human as he sits down in disappointment. Hikaru and Peebo tries to cheer him up for his actions and Jun also mentions about Mason talking about Doctor Man is the Prince's father and Shirou also wants to know about it and Shingo also noticed that Doctor Man is the creator behind of the mechaclones which is his creations and Shirou knows that there's more than the meets the eye.
Meanwhile at the Neo Empire Base, Doctor Man fixes the Prince's brain that he impacted due to Ryuta's angry words. He is also responsible in creating the mechaclone in the image of his estranged teenage son, Shuichi Kageyama which he strips off his human emotions and becoming the perfect killing machine. However, Peebo alerts Shirou and the group about the Grotes Canth which is spotted in the city and the group as Bio Team rushes with their vehicles to prevent the Prince for doing more damage as they hurried while Pink5 activates the Super Speed.
The Bio Team are later confronted by Grotes Canth which is piloted by the Prince as he gets off to confront them. Therefore, Mason and his squad arrive to join the fray. The Biomen manages to defeat the mechaclones with their weaponry while Blue3 goes head to head against the Prince as a mechaclone. The Biomen are dealing against Zygorn and the Prince makes an advantage to zaps Blue3 with electricity from his stick as he manages to counterattack him with his Bio Sword finally injure him on purpose who manages to get back to his mecha. When Zygorn defeats the Biomen, Blue3 manages to electrocute him by throwing his Elec Sword to the chest. They later defeat Zygorn with Bio Electron Beam.
When he summons the Bio Dragon from Peebo to form two Bio Jets into a Bio Robo, The Grotes Canth manage to zap them which the Bio Robo counterattacks with a Bio Cutter with it's sword slashing the wires and it's core of the mecha which is no effect due to being reassemble and Prince begins to attack them as it manages to release from the wire. Blue3 tells Red1 to distract him with Bio Missile as he successfully do it directly hit it's core from the wire making him vulnerable and it finally defeats it with another Bio Cutter and the Prince is destroyed along with his mecha in explosion.
Due to the Prince being decapitated by the Biomen, Doctor Man coughs in a weak state yet again as his plans are thwarted again and walking away. Although, Mason has his motives to take over when Doctor Man is distress in conquering the Earth is taking it's toll and he has to retire. Doctor Man reveals to be a human with cybernetics as he fixes his left chest replacing with electronic lung to eliminate all his respiratory problems. He knows that someone will succeed to his mantle but he cannot entrusted to give to his henchmen and the success will be his rule someday.
After defeating the Prince, the two mothers are watching their children are riding ponies while Shirou and the group watches and Ryuta was happy that they thwarted Doctor Man and it's advanced creations as Shiro replies that Doctor Man has to keep on trying and Hikaru tells them that they can manage to defeat the Grotes Canth and Shingo remarks that Doctor Man is still a pest as he patted on Ryuta and he replies that he's a pest and most deadly ever and Shirou convinced them that they are Biomen and the Earth will remain to be free. He and his group are later seen happily walks away.
- Shirou Gou (郷 史朗 Gō Shirō): Ryōsuke Sakamoto (阪本 良介 Sakamoto Ryōsuke)
- Shingo Takasugi (高杉 真吾 Takasugi Shingo): Naoto Ōta (太田 直人 Ōta Naoto)
- Ryuuta Nanbara (南原 竜太 Nanbara Ryūta): Akito Ōsuga (大須賀 昭人 Ōsuga Akito)
- Jun Yabuki (矢吹 ジュン Yabuki Jun): Sumiko Tanaka (田中 澄子 Tanaka Sumiko)
- Hikaru Katsuragi (桂木 ひかる Katsuragi Hikaru): Michiko Makino (牧野 美千子 Makino Michiko)
- Peebo (ピーボ Pībo, Voice): Yoshiko Ōta (太田 淑子 Ōta Yoshiko)
- Doctor Man (ドクターマン Dokutā Man): Munemaru Kōda (幸田 宗丸 Kōda Munemaru)
- Mason (メイスン Meisun): Hirohisa Nakata (中田 博久 Nakata Hirohisa)
- Farrah (ファラ Fara): Yōko Asuka (飛鳥 裕子 Asuka Yōko)
- Monster (モンスター Monsutā): Strong Kongō (ストロング金剛 Sutorongu Kongō)
- Prince (プリンス Purinsu): Hidenori Iura (井浦 秀知 Iura Hidenori)
- Psygorn (サイゴーン Saigōn, Voice): Keisuke Yamashita (山下 啓介 Yamashita Keisuke)
- Zyuoh (ジュウオウ Jūō, Voice): Masahiro Anzai (安西 正弘 Anzai Masahiro)
- Mother: Miki Shimamura (島村美妃 Shimamura Miki), Yorie Terauchi (寺内よりえ Terauchi Yorie)
- Boy: Kentaro Ishizeki (石関賢太郎 Ishizeki Kentarō)
- Although not announced during their final blow, Grotes Canth is defeated by what will become Bio Robo's most powerful move during the first half of the series, the Weight Attack. This will be Bio Robo's most powerful ability until the devising of Bio Particle Cut with Gear's development of Neo Mecha Gigan in the second half.
Choudenshi Bioman Volume 2 features episodes 12-21.