After the events in
Owarimonogatari where Koyomi saves Ougi Oshino we see him looking in a mirror and being transferred into another version of the world he knows. There are many odd things to note:
- Karen is short.
- Hanekawa is in her Black Hanekawa form fully.
- Hachikuji is in the body of an adult.
- Kanbaru embraces the form of Rain Devil and seeks to kill Koyomi
- Sengoku resembles her inner self and the frustration she lets out
- Oikura is living with the Araragi's and she is expressive.
- Shinobu is in her human form
- Ononoki being much more expressive.
- Only Tsukihi is unchanged and Hitagi doesn't show up.
Given that Koyomi was transferred from the mirror, it could very well mean that everyone is their true selves that they locked away. The Mirror which is a reflection of you exposes those.
- Karen has insecurities about her height.
- Hanekawa being more laid back
- Hachikuji getting to live as an adult.
- Kanbaru wanting her desires to kill Koyomi.
- Sengoku letting herself be loose.
- Oikura able to express herself to her desires.
- Shinobu getting to live as a human.
This gives the solution to Koyomi of traveling back to his world. As he tries to do that, he receives help. Naturally, like he has done all of this time, he wants to seek out Shinobu's help. However, the issue is: Vampires don't have a reflection, so naturally, Shinobu can't exist in this world. But she does exist as a human princess. Her advice is to seek help, but what is this help?
With the help of Ononoki, he is able to infiltrate Kanbaru's house. Where he meets Kanbaru's mom, Tooe Gaen. Given that Izuko Gaen mentioned that Koyomi reminds her of her sister. As he meets Tooe, it is clear how she is a different kind of genius than Izuko and Hanekawa. Izuko's genius comes from eliminating what she doesn't know so she knows everything. Hanekawa utilized both as her tools. Using what she knew and what she didn't know to aid in her solution. For instance, finding Meme Oshino.
According to her with what they are missing is that you can know something, but be wrong. Which is a very true thing in life. What if you are wrong with what you know or don't know? Does it make sense about what you know? Within your knowledge, can you understand it as well? There is also the interesting aspect that her family was one of monster creation. Which might be more important in the long distant future. She talks about facing your other side or other half. Essentially, how you face with what you are holding deep inside. She mentions the Rainy Devil was her other half, and it consumed her and turned her into a monster. Tackling your other half is the first important key.
As Koyomi meets Ougi they have an interesting conversation. It is mentioned how in a mirror 20% isn't shown when it is reflected. That gives Koyomi the clue that he never existed in this world. As we know, Koyomi is a very empathetic guy, he will resonate with that 20% of which is missing. So, for many people it can be seen as their regrets. So all the people he sees that is their regrets or that is how it seems initially. The real twist is that there is no world to go back to. He is already in his world. With his vampire skills, he pulled out the lost 20% and created this world into a mirror world. This gives the fear of is this permanent?
Switching topics, Ougi talks about the decision Koyomi made in saving her. It is an important point going forward that the specialists didn't agree with his decision. What does this mean exactly? It is much more so the term of Koyomi and Ougi being partners. This does imply that in the future Koyomi and Ougi are in danger. The idea that Ougi is a quasi-darkness that can't allow a happy ending is a fear they have. The darkness they act like one, but really isn't. Darkness that only exists for Koyomi's regrets. I assume that they fear that the side effects could be deadly.
At the end of the day, Ougi is Koyomi's partner, much like Shinobu. The idea is that he cleans after he and she cleans after him. He will protect Ougi and Ougi will help him in his tight spots. She offers a holy instrument which will take care of the 20%. Ougi leaves with an important question and that is who is Koyomi Araragi?
The answer to Ougi's question of "Who are you?" requires self reflection on Koyomi's part. Koyomi is an empathetic guy, and he wants to help out everyone in need. However, there is a lesson that if you dwell too much on your past it can be a negative burden. For Koyomi the changes in this mirror world represents what he regrets he couldn't do. He pulled it out of the mirror because he didn't want to lose it.
- For Karen not teasing her as much about her height.
- For Hachikuji not being able to change the past so she can live a normal adult life.
- For Kanbaru being unable to help her issue with the Monkey's arm and not being able to fix it by the time he graduated.
More beyond those. The lesson Koyomi learns is that, yes he has regrets for things he couldn't do in the past. That is a part of life. We are all going to have regrets, but how we live and move on from them is key. Koyomi needed to learn that lesson.
So why was Tsukihi the same as she was previously? What is Koyomi's regret regarding Tsukihi? Well, we know that she is the apparition of the Phoenix and you can imagine not being a regular human like him and Karen is what he regrets. While on the surface she looks the same, but in this world she isn't the apparition of the Phoenix. This is a regret like the others, but obviously this is something way beyond his control. These are the regrets that are the hardest to move on from.
One really sweet highlight at the end of this was how come we never saw Hitagi. There is nothing in his life that he regrets about with Hitagi. His love, trust and relationship with her and how they have developed that are things he has 0 regrets on.