Guyver Bio-Booster Armor

Guyver: The Bioboosted Armor (強殖装甲ガイバー, Kyōshoku Sōkō Gaibā?) is a Japanese anime series based on the long-running manga series written by Yoshiki Takaya, adapting chapters 1 - 59 (volume 10) of the manga. The production was in association with ADV Films and Kadokawa Shoten. The series first episode aired in Japan on August 6, 2005 and the last episode aired on February 18, 2006.

A test type Zoanoid, disguised as a normal man, escapes from an organization called the Chronos Corporation with a bag containing three items called the Guyver Units. Chronos soldiers attempt to recover the units from the test-type but are unsuccessful; the test-type was discovered with a grenade in his possession and used the grenade, killing himself and scattering the Guyver Units around the area. Meanwhile, two young high school students, Shō Fukamachi and Tetsurō Segawa come across one of the lost Guyver Units. Curious as to what the unit is, Shō accidentally activates the unit which then merges with him, becoming "Guyver I." Now, Shō must fight for his life and those that are close to him against Zoanoids sent by the evil Chronos Corporation that are in pursuit for the Guyver Units.

Most, if not all, of the characters from the original Guyver manga series appear in the new Guyver anime series. Several characters from the new anime series have undergone a slight change of design from their previous looks from the past animated OVA and manga series (see Guyver (OVA) and Guyver: The Bio-Boosted Armor). For instance, Shō has a different style, brown hair rather than his original black hair. Mizuki now has black hair in the 2005 series instead of her brown hair from the previous series.

Source: Wikipedia