"Learning from me or from your brother, it's all the same. You just need to think it through, you're more suited to the path of magic. With focus and diligence, then maybe you can hope..."
"So that's how it is, hehe, I got it, Master Sister..."
"What nonsense are you spouting!!"
"Master~~~ I know you love me, but my brother loves me too. This way I can stay by his side all the time and constantly watch over him for you... Ow, stop hitting me..."
"Sigh, no matter what I say, you don't take it to heart. Well then, I'll just let you bump into a big problem and come to your rescue then."
"Master, why would you curse me..."
"Impudent! Looks like I need to put a Tight-Binding Spell on you ahead of time. Disrespectful and clueless about the world!"
"Master, Master have mercy, I won't dare anymore, I won't dare!"
In the dead of night, the whole Mage Tower was silent. A dashing thief found a "carelessly" left "flaw" by the lady of the house and sneaked into her boudoir.