Instruction of G4

After 4 years Yume,Laura,Ako and Mahiru came back to Four star Academy as a unit named G4. But the t weren't alone they had also Koharu as their manager. What will happen if M4 and S4 will see the 5 Girls after 4 years. Will they fall in love? will they only be friends? Or are the girls already in relationships? Find it out in the Book return of the four stars