Yuri is an android created by a highly advanced race. She was discovered in some ancient ruins on the moon during the storyline of "Galaxy Fraulein Yuna 2: Eternal Princess". Yuri came home with Yuna and lives at her house, and then becomes Yuna's best friend. At some point, she becomes the Kagurazaka family's adopted daughter, making her full name Yuri Cube Kagurazaka. Yuri is best known for her insatiable appetite, which has led some fans to speculate that she may have a black hole for a stomach. Yuri is immensely strong though performing feats of strength depletes her energy reserves, at which point she must eat to regain her strength. Quite humorously, her appetite is also her biggest weakness, as Yuna has been seen bribing Yuri with food on more than one occasion.

In combat, Yuri not only uses her super strength, but she uses a weapon called Twin Dragon Fangs that can interchange to Sword mode or Gun mode. Also, she can create reinforced parts for upgrading El-Line to the more powerful El-Line Noi.

Source: Wikipedia