Karara

The famous daughter of Dobaba and daughter of the Keroro Platoon. She is often put in danger until rescued by members of the Keroro Platoon. She appeared with her childhood friend, Taruru until Taruru joined the Garuru Platoon and was replaced by Karara's best friend, Chiroro.

Karara was scheduled by her father to be married against her will, so she left Keron (apparently with Chiroro) and came to Earth. She is a green Keronian Tadpole with a circle with a line through it as her symbol. She was temporarily enrolled as the Private Third Class of the Keroro Platoon but causes trouble and is rescued by Tamama from her father who attempted to kill her as punishment for disobeying him. She had gained feelings of love towards Tamama, Dororo and Giroro, and even attempted to marry Kululu. She was kidnapped but was rescued by Dororo and she was gifted with a sword (Chiroro had one too) that when freed from its chain gives her a ninja's clothing along with a white scarf and a silver mask over her eyes. She assists the Keroro Platoon in rescuing Chiroro from Viper until Karara gets taken hostage by Keroro in a Viper Pekopon Suit. While a reformed Viper grabbed Keroro, Dororo destroyed the Pekopon Suit with his attack "Blade of the Phoenix". Karara landed in the arms of Giroro and thus, she fell in love with him while Keroro was arrested. While entertaining the angry 753, Keroro gave advice to Karara and Chiroro, and then they had successfully turned 753 back to normal and thus, she fell in love with Keroro.

(Ref: Wiki)