Question: are miyuki and tatsuya really siblings?
Answer: Shiba Tatsuya. The relationship between Tatsuya and Miyuki is one of the focal points in the story of Mahouka Koukou no Rettousei. Tatsuya and Miyuki do not act as normal siblings should, and instead, act more like lovers. ... For her, there is no greater joy than serving and taking care of Tatsuya.