Schoolgirls

The schoolgirls are a long-haired brunette and short-haired blonde in matching uniforms who in their first appearance comment on Frank talking to himself on a bench. This means either that they are hallucinations, that Frank was hallucinating Wayne and Guy, and possibly that Wayne and Guy were ALWAYS hallucinations.

Although Frank's neighbor appears to have seen the two, which could indicate that he is also part of the hallucination.