OCs Insert - Demon Slayer

Miko Shoko is a young girl who becomes a Demon Slayer. In just two weeks, she's mastered her own breathing, Crystal Breathing, and her unidentical twin, Miru Shoko has matered Blood Breathing. They kill Lower One together, and become the Crystal and Blood Hashira. Miko finds the Mist Hashira, who's now goes on joint missions with her, very interesting. But she doesn't know that Muichiro Tokito likes her back. Miru underetimates herself, and find her and Miko the strongest Demon Slayers in the entire Corps.