173 light-years away from the Earth, there is a planet called “Monchacha”, where have creatures like human with wisdom and mind. However, the citizens of Monchacha are not happy. The president of Monchacha has tried almost everything to improve this problem but nothing has worked. One day, the president heard that there is a Hidden Book on Earth that could help solving this problem. Therefore, he has sent 4 investigators, Do, Re, Mi, and Fa to conduct the investigation on Earth. When Do, Re, Mi, Fa landed on earth, they accidentally ran into Lily and Max, who have just finished school. What will happen between them? Could Do, Re, Mi, Fa help the president to find the Hidden Book? Would you like to join them for the adventure?