Robin Sena arrives in Japan to replace a fallen member of the STN-J. Engrossed in a witch hunt, the members of the team are unaware that this quiet 15-year-old is the new Hunter and brush her off. When they finally corner the Witch will they come to appreciate Robin's power?

The STN-J is called in by the local police when a dried corpse is found. When Robin finds a dead insect on the body the team goes on a hunt for a Witch who can control insects. They find that there were two previous victims found in the same condition. The cases point to a similar rash of deaths leading back hundreds of years. Apparently, all the dead are Witches. Is the STN-J dealing with an immortal who feeds on Witches?

When Amon hands Robin the file for unsolved and possibly Witch related murder cases, she finds a string of deaths that occurred in the very same park she walks through to go to church. There is a young girl who paints landscapes there every day and Robin becomes concerned for her safety. She teams up with Ms. Karasuma to investigate the park, but is she sure the murders were caused by a Witch?

When Robin's Vespa runs out of gas during a rainstorm, she is picked up by a kind-hearted motorist. Shortly after dropping Robin off, the woman is killed in a horrible accident. Upset over her death, Robin senses that a Witch may have been involved. Together with Amon, Robin pushes forward to uncover the truth.

When a suspected thief's wrecked car is pulled from the harbor, the STN-J suspect there is more going on then a mere accident. When the go to question the suspect, however, he flees in his car, crushing Karasuma's vehicle with a powerful blow in the process. But, was it the thief doing the crushing or a more sinister force?

As part of an STN-J a sting, Dogima and Robin take jobs as waitresses in Harry's bar. The man they're hunting was once betrayed to the STN-J by his own father, the owner of Harry's. As they wait for the prodigal son to return, the STN-J begin to realize that they're not the only ones after Yutaka Kobari.

Robin and Amon finally confront Zaizen and learn the truth about Robin's existence. To Zaizen's surprise, instead of being traumatized, Robin is instead strengthened with resolve. Now Robin and Amon must stop Zainzen's final solution for the sake of both Witches and Humans alike.