Episode 4 of Shikabane Hime: Kuro, “Form of an Abnormal Moon”, starts off with Sougi driving to where the shikabane had appeared in the previous episode with Ouri and Itsuki as passengers. On the way, he tries to explain why a shikabane hime should never be considered a normal human based on his own personal experience, and the rest of the episode is basically about the past of Sougi and Itsuki. Meanwhile, Ena has dressed up in preparation for the attack on Makina and is looking forward to the look on her face.
Back to the past, as we saw in the previous episode Sougi did not have a clue about the shikabane hime, so Itsuki had to explain it all herself when they met. Sougi found it hard to view her as anything more than an ordinary girl, despite Umehara’s words to the contrary that stress that Sougi should always remember that a shikabane hime is not a human girl. We also get a chance to see Umehara’s other shikabane hime, Touma.
The way Sougi thinks about Itsuki doesn’t change even after their first fight against a shikabane, which didn’t went well although they did ultimately emerge victorious. Sougi was injured while trying to help Itsuki, even though she would have recovered much quicker from any injury than he could. And Itsuki went through what many rookie soldiers go through: she froze in the face of the enemy, even suffering from the fear of death despite already being technically dead. But they did emerge victorious and relatively unscathed, so all was well for the time being.
The two practically start a romantic school life story when Itsuki is transferred to Sougi’s school as a student. While the reason for her transfer was to strengthen the connection between the contract monk and the shikabane hime, it’s rather surprising to see how Sougi didn’t even know it was going to happen until Itsuki showed up at school. It’s quite obvious that Itsuki only has eyes for Sougi, although the look may have been misinterpreted by most, and Sougi’s close friend Tomoharu is quite impatient that the couple are not hooking up officially.
This all changes when Tomoharu dies. His whole family died in a car crash caused by young people racing cars down the road, so his obsession is revenge against those responsible for his family’s death, and his power is the ability to control cars the way he wants. And his targets soon extend from just the demographic matching those who were responsible for his family’s death to anyone in general. Sougi and Itsuki are responsible for taking out Tomoharu.
Unfortunately, Sougi cannot bring himself to order the girl he loves to destroy Tomoharu, a close friend of theirs. He might know intellectually that a shikabane loses most of its rationality and that there’s very little that can be done to help one, except perhaps making it a shikabane hime, but emotionally he can’t accept inflicting emotional harm on Itsuki and to a lesser extent physical harm on Tomoharu. This is a mistake, as Tomoharu almost manages to kill Sougi. And Sougi witnesses a frightening aspect of Itsuki when she’s severely damaged while protecting Sougi. In fact, Itsuki loses control of herself and nearly kills Sougi when he tries to save Tomoharu from her attack. This is the event that changed the relationship between Sougi and Itsuki completely, as Sougi falls into the trap of a false dichotomy. Sougi is now determined to view Itsuki as something completely other than human, and Itsuki doesn’t say anything about it since she can’t disagree with the assessment.
Back in the present, Sougi and Itsuki are confronting Tomoharu again, and this time Sougi orders Itsuki to deal with him. Meanwhile, Makina is being escorted to be imprisoned again, given her irrational state and inability to be a proper shikabane hime, but we see Ena’s plan being enacted. Given whose appearance would make the most impact on Makina, it’s a pretty obvious guess who Ena appeared as: Keisei.