Everyone so far is on the same floor. Aiden has a solo room unless another male character is brought in. 
Masi and Ryuu are neighbors. 
Eira and Mizuchi are across the hall
Reina and Misaki are beside them across from Masi and Ryuu
Convenient?
Yes... 
Do I regret it?
No >_>

1) Aiden

2) Masilait
2) Ryuu

3) Mizuchi
3) Eira

4) Reina
4) Misaki