User blog comment:Jopjopjop/Volume 19 Spoilers/@comment-2143738-20141206004048/@comment-24421137-20141206011443

The spoiler showed that Tsubaki is definitely not Kiba's girlfriend in fact I am pretty sure that it can be inferred that by "Girlfried" it might be meant a friend that is a girl. Any who the girl you are wondering about is named Tosuka a girl who was also from the same institute as kiba, however she still retains her youthful appearance, and was able to survive thanks to her sacred gear which uses a special barrier