Flying Hearts was once the most popular girl group on Earth, and the current most popular idols in the entire Federation. Their small bodies blasted out incredible singing energy; their courage after facing consecutive attacks by terrorists, their pure and lovely appearances... these had brought up a Flying Hearts whirlwind in the Federation.
Other singers were struggling with their concerts and were striving for a satisfactory attendance rate; they thought hard to come up with new tricks to attract people. Flying Hearts, on the other hand, was having struggles with stadiums being too small for their audiences.
