Kingdom Hearts Birth By Sleep

Long before Sora was chosen by his Keyblade, the worlds' safety lay in the hands of the true Keyblade Masters. Four youths: Terra, Ventus Y/N and Aqua they have been training long and hard under Master Eraqus to prove that they, too, exhibit the Mark of Mastery. Y/N L/N is the youngest Keyblade wielder ever! She is 10 years old and is also the youngest wielder to take the mark of mastery exam.