User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-3965848-20150415124246/@comment-3965848-20150415132450

I just think it would be best to be around someone she knows considering what shes been through and within the ORC she could learn to control her SG.

And the fact that Tsubaki goes to collage means she isn't as close to as Tosuka is, and someone could tell her what's he doing (remember she's in contact with Issei) and she would still come together with everyone whenever some disaster happens.