Schwi was the first Exmachina to be introduced in Tet's story. In the story she seeks to understand the human heart and was found by Riku. She looks like a young human but with several differences, being two tails coming out from her back and other machine like features protruding from around her body. She bears many similarities with Shiro.
Her behavior is similar to that of a stereotypical artificial intelligence. She can absorb and process data and intelligence very quickly and act in the appropriate manner, a unique characteristic of her race. However, she seems to have difficulty in comprehending emotions and desires, otherwise characterized by her as the heart.
(Source: No Game No Life Wiki)