A Slytherin Without Ambition
2.
Slytherin isn't just the house for the ambitious. It's the house for people who'll do anything for those ambitions.
Yuzuki at least is straightforward. She jabs her wand into Ruuko's chest, sees Ruuko has absolutely no interest in her brother (or boys at all, really – with Ayumu the only exception – considering what a disappointment her father had turned out to be) and decides Ruuko will make a fine friend. And it's a good thing she does, because Ruuko somehow gets onto Akira's bad side within seconds of meeting her, and having Yuzuki standing beside her is a huge comfort.
Doesn't stop Akira from playing rather cruel pranks on Ruuko's other new friend at Hogwarts, the meek Hufflepuff Hitoe, in retaliation.
Also doesn't stop Ruuko from accidentally firing a blasting course at the other's face. And it's not for self-defence, or defending Hitoe who's cowering behind her. It's only because Akira needs to be taught a lesson and the spell's shot out from her fingertips before she's even drawn her wand or thought of the spell she wants to cast.