Kenshin receives a request from the police chief, asking for his help to take down "Kurogasa," a serial killer who has been repeatedly targeting former Revolutionary warriors. Kenshin and Sanosuke go to escort Jusanro Tani, who received a letter containing a death threat. As warned in the letter, at 1:00 a.m. sharp, Kurogasa appears. His true identity was Jine Udo, a vagabond slayer who had made a name for himself in the assassination business since the Bakumatsu Era.

Sanosuke's friend has died from an opium overdose. However, Kenshin and Sanosuke are perplexed at how he even got his hands on the drug, since opium is banned and too expensive for the average person to afford. Then a mysterious woman, Megumi Takani, appears before them. Kenshin and the others fight off Kanryu Takeda's private army who is trying to capture Megumi. However, Megumi is carrying opium...

The pursuers from the Oniwaban Group haven't made an appearance for over a week, and during this time Megumi familiarized herself with the Kamiya Dojo group. Sanosuke, however, was still unsettled and feeling frustrated knowing that Megumi was the one who made the opium that caused his friend's death. Then one day, Megumi suddenly disappears. In a letter they found from her, it stated that she had left of her own volition, but Kenshin and the others found this to be unnatural. They decide to head to Kanryu Takeda's residence, the man who was sending spies after her.