Masaru Aso

Kamen Rider ZO (麻生 勝／仮面ライダーZO, Asō Masaru/Kamen Raidā Zetto Ō?) is a kamen rider that appears in Kamen Rider ZO.

Masaru Aso
Masaru was originally an assistant to Doctor Mochizuki until the doctor conducted experiments on him. Horrified at being made into a grasshopper-like cyborg, Masaru went into hiding in the mountains for two years until he awoke with an unconscious urge to protect Hiroshi. Though he hated Mochizuki, Masaru eventually forgave him before learning the man was telepathically communicating with him.

Kamen Rider ZO
His only attacks are ZO Punch (ZOパンチ, Zetto Ō Panchi?) and ZO Kick (ZOキック, Zetto Ō Kikku?). ZO also rides on the Z-Bringer (Zブリンガー, Zetto Buringā?), built by Dr. Mochizuki. Though resembling a regular motorcycle, the Z-Bringer changes along with ZO with ability to reach speeds up to 1300km/h and resist heat up to 1000 degrees. ZO can use the Z-Bringer to execute the Z-Bringer Attack (Zブリンガーアタック, Zetto Buringā Attacku?). Another of ZO's features within his insectoid head called a Break Dousar (ブレイクトゥーサー, Bureiku Doūsā?), a breathing appartus stored around the mouthplate that shoots out vapors, baring resemblance to fangs when extended.