Twilight, Hawk Moths at the Lantern (宵闇, 夕顔別当の燈 Yoiyami, yūgaobettō no to) is the second episode of Hakuōki OVA (2021) that is meant to be an extension of the main plot of Hakuōki: Shinsengumi Kitan. This episode gives more insight about the story from the Shinsengumi members' point of view rather than Chizuru's.
Plot
Harada encounters Sen who has come to meet Chizuru and he has to inform her about Chizuru's disappearance. When Sen blames him, he takes it as he feels like it is the Shinsengumi's fault and there is no reason to make excuses.
Itou, Kondou and Hijikata discussing the Tosa investigation
Heisuke and Shinpachi also blame themselves due to not being able to find anything out. Sannan confirms that the inspectors that went to investigate the Tosa Domain and ended up dead were killed by Rasetsu. Hijikata tries to convince Kondou to raid the Tosa territory but Kondou hesitates afraid to jeopardize the Aizu reputation. Eavesdropping on their conversation, Itou walks in and offers his assistance. Hijikata is forced to accept it.
Saitou finds Okita
Next morning Hijikata notices that Souji has not eaten his food. Other Shinsengumi members confirm that he was looking for Chizuru all night and has already left for patrol, and everyone is worried about his health. While on patrol, Okita notices suspicious samurai and follows them only to be stopped by Saitou. He complains about Hijikata's decision to seek Itou's help but Saitou assures him that the Vice-Commander is simply doing his job and gives him some food.
When Itou enters the Tosa mansion, he stumbles upon Kazama who is giving a warning to the Tosa Domain as a representative of Satsuma. He leaves without replying to Itou's questions followed by Amagiri.
Kaoru, dressed as Chizuru, gives orders to the Tosa samurai notifying them that the Shinsengumi are coming soon. Meanwhile, the real Chizuru is tied up and hidden in a basement, worried about Sakai. Sakai is also hidden on the Tosa territory trying to understand how his grave injuries have healed without a trace and mistaking Kaoru for Chizuru.
Sano and Heisuke fall in a well
Shinsengumi conducting an investigation in the Tosa mansion
Yamazaki informs Harada and Heisuke that someone has seen a person that looks like Chizuru. They follow the lead and end up in a deserted area with ruined houses and no inhabitants. They instantly see "Chizuru" and call for her but she does not respond and runs further into the ruins. They follow her and fall in a deep well with ice-cold water. Nobody is around to hear their screams and they realize that it was a trap. Satisfied with his actions, Kaoru leaves and, upon seeing children, remembers his childhood with Chizuru and promises to rebuild the Yukimura family along with her.
In the evening Hijikata announces that with Itou's help they are able to conduct an investigation on Tosa. Assuming Heisuke and Sano can help themselves, nobody intends to look for them and everyone decides to direct the attention to finding Chizuru and Sakai instead. Okita is sure that he will be the one to find the girl. Saitou asks the Shinsengumi are permitted to kill in case the Tosa samurai decide to fight back, and Hijikata confirms.
While the Shinsengumi raid the Tosa mansion, Kimigiku and Senhime are running near the ghosted part of the city, and Kimigiku hears Sano's voice asking Heisuke not to fall asleep in the cold, and the females decide to save the guys. At the same time, Kaoru encounters Kazama on the way back to the Tosa mansion and tries to fight, but Kazama wins fast and easily, so Kaoru runs away with Kazama following him to the lair.
Kazama saves Chizuru
Hearing that the Tosa samurai are planning to kill her because the Shinsengumi have arrived, Chizuru tricks them and escapes running out of the basement. The samurai catch up with her but Kazama attacks them and saves Chizuru. Given a hint by Senhime, Heisuke and Sano also arrive at the mansion and start fighting the Tosa samurai while Chizuru and Kazama escape and meet Sano and Heisuke later who instantly assume that Kazama is one of the enemies and start attacking him. Okita joins as well, but Kazama defeats them all without breaking a sweat. Chizuru tells Okita that Kazama actually saved her, and Amagiri urges Kazama to leave and let the Shinsengumi finish the job. Kazama instantly leaves promising Chizuru to come back for her.
Okita pretends like he was not worried sick about Chizuru and pats her when she thanks him. Upon returning to the headquarters, Chizuru thanks everyone and tells them that the rogue samurai who captured her are plotting to assassinate the shogun. When left alone, Hijikata apologizes to Chizuru for putting her in danger.
The trio choosing material for Chizuru's yukata
Next day, the trio notice that Chizuru feels sad because of Sakai who is likely dead but still not found, and they decide to give her a present to cheer her up. They choose a shop where they can order a yukata (female summer kimono) for her. They start looking through the colors and patterns arguing which one is better but the fake Shinsengumi appear to rob the shop, and Sano rushes first to confront them. Shinpachi and Heisuke join him, and the trio defeats the rogue samurai with bare hands.
Meanwhile, Sakai is still with Kaoru and suffering from the bloodlust.