Isaac and the Black Sword Knights are responsible for training the Maihama army. While he's in Maihama Isaac gets to know the new crown prince of Maihama, a young boy named Iselus.  Iselus respect looks up to Isaac and respects him.
At a party for the crown prince's birthday, assassin's make an attempt on his life.
You're working hard, aren't you, Isaac?
Ja, du gibst dir wirklich
alle Mühe, Bruder Isaac.
Trabajas duro, Isaac-kun.
Vous faites du beau travail,
mon « petit » Isaac.
Ti stai proprio impegnando, Isaaccuccio.
Você está se empenhando
 bastante, Isaac-kun.
А ты у нас не промах, дорогой Айзек!