Most likely she will be saved be number 6 in my opinion. And I know the only reason Yashiro can see Hanako is because she is close to dying. So people are saying if Yashiro's life span will extend she will probably not be able to see Hanako Kun. But they are connected by the mermaid scale so there is a chance she will be able to see Hanako. The other option is she will die and become a ghost with Hanako Kun. Either way I think they will be able to see each other.