When those two girls—critters?—line up, a kind of, how should I put it, microcosmos, doggy whirlwind materializes in the form of a cog wheel and an overwhelming disrupting force appears in the gap between them... When a subject is exposed to that forcefield, it gets infected by the virus.

And after infection... The true nature of the victim is forced to surface, I guess...? ...Yeah, the subject gets transformed into an animal, or something...

Wait, you just cut all the corners in the last part of your explanation, right!?

Huh... Well, I don't really get it, but it's basically a link tactic...?

Eeh... Yep, sorry, I have no idea what you are talking about.

Anyway, let me continue. Victims infected by the virus suffer from the effect which brings them closer to their "true form". On the other hand, those who don't have such a form are not affected.

That's why the virus does not manifest in humans. In fact, the risk group is limited to youkai who possess an original form.

The virus itself is rather weak and will expire naturally over time.

And now... I'm naming it "Barkricon virus"... Virus name credit to BPilgrim.

What now!? Gross!!

The lifespan is expected to be half a day at most, after which the subject should revert to its former self.

A●liaaa! His last words, the name of his lover.