She is the second person who joins Gintoki's freelancer business in the series.

She is a young alien girl who belongs to the Yato Clan, one of the strongest and most bloodthirsty of the Amanto races though Kagura rejects that part of herself.
The Yato have "translucent" skin that is highly sensitive to sunlight, so Kagura carries a umbrella at all times. The parasol is also the Yato clan's weapon of choice; Kagura's umbrella is bulletproof and fires bullets from its tip. Because of her Yato blood, she is extremely strong and can stop a speeding motorscooter with one hand. However, she cannot control her strength perfectly; most of her pets, with the exception of Sadaharu, have all met an untimely demise at her hands. Kagura also has an unusually strong appetite, making her capable of consuming large quantity of food within a matter of seconds.

She came to Earth to earn money for her family and to escape her violent Yato heritage. She found work fighting for a gang of hoodlums but when they ordered her to kill her target, she ran away. Not long afterwards, she met Gintoki and Shinpachi, when they accidentally run over her with Gintoki's scooter. After they help her to make a clean break from the gang, she intimidates Gintoki into hiring her.

Kagura and Gintoki have an odd father-daughter-like relationship and she commonly imitates his bad habits. She is highly protective of Gintoki, and affectionately refers to him as Gin-chan.

She appears in a Sket Dance crossover episode alongside Gintoki and Shinpachi, in episode 26.

Source:WIkipedia