for kids. There, you learned it, right? Take it back."
Muen took the fully solved Rubik's Cube, happily hugged it, and crawled under the covers.
Before long, the rhythmic sound of Muen's breathing could be heard.
"Muen?" Noia called out to her sister.
Seeing no response, Noia quietly got out of bed. Then, she took out her small wooden box from under the bed and opened it.
Inside was a piece of black metal fragment and a piece of paper with her name written. She removed her little Rubik's Cube from her pocket and carefully placed it in the wooden box.