Sannan has been using materials left behind by Kodo to continue to try to improve the medicine in secret. He drinks the medicine and transforms into something which is no longer human. After seeing the wound Sannan infected on Chizuru heal in an instant, Hijikata asks her if she's a rasetsu, but...
Later, the commotion over Sannan adds to the decision to move the Shinsengumi headquarters to Nishi Hongwanji. Chizuru continues to search for her father, but she is unable to find any clues to his whereabouts. Then one day, Chizuru happens to overhear Okita's secret.
Sannan-san has made his own improvements 
to the medicine. I know that.
أجرى سانّان-سان تحسيناته الخاصّة على
الدّواء. أعلم ذلك
unternahm Sannan-san seine
eigenen Anpassungen an der Medizin.
para que los sujetos
conservaran la cordura.
para que los sujetos
conservaran la cordura.
ses recherches
pour mettre au point l’antidote.
Sannan-san ha apportato
 delle modifiche alla medicina.
com o intuito de reter
a sanidade das cobaias.
препарат, чтобы подопытные
сохраняли рассудок.