Souka was born into the Tsukihime family, landlords of the entire region descended from a house of samurai. Living in a temple deep in the mountains of Nagano, they are known as the "mountain kings" with a bearing greater than that of the Tohno household. Raised in such an environment, Souka rebelled and developed an interest in rock music. She came to be roommates with Akiha and Hanei at the Academy, and made plans to live together with Hanei and attend college after graduating from high school.