Leia is Nadeshiko's faithful two-tailed cat Yōkai companion who is Nadeshiko's main method of transportation. Leia usually appears to be a small kitten-sized feline with two tails. However, she has two forms: one of a small kitten, and one of a large cat resembling a saber-toothed tiger. In her full-sized demon form, flames emerge from her feet and tails and she can take on even the most dangerous of demons. She is very intelligent and fiercely loyal, mostly so to Nadeshiko because they 'were together from the beginning. Later, she is shown to have become loyal to the entire group. She is also particularly close to Meilssa, who are often seen playing together. This is probably because of their connections as being demons, and also because they are so young and both so playful.
At the end of the series, three years after Naraku's defeat, Leia joins Kaine as he trains to become a demon slayer. Meanwhile, Nadeshiko is starting her new life and family with her child.
Although she is currently Nadeshiko and Kaine's pet, she was originally the companion of Chloe, the miko who recreated the Shikon Jewel.