Кэйсукэ Юки

Миаки's older brother. A funny young man, a high school student. He was the first person to whom Miaka told about her adventures in the book, although he did not believe her. He tried to stop Miaka when she was leaving her world again. After his sister's disappearance, he continued to read the mysterious book. Keisuke, together with his friend Tetsuya, tried to help Miaka escape and figure out what this book is and where it came from.