Minamoto Kou tells Yashiro Nene about a person he met during the Study Camp, who told him the secret to becoming a supernatural. Nene asks if he was referring to becoming one through means of dying; Kou says no, but seems hesitant to continue further and attempts to leave the room. Nene grabs his arm and asks Kou if anything is bothering him. Kou remembers his deceased friend, Mitsuba Sousuke, who turned into glass during the severance. Kou tries to say something as Aoi Akane storms into the room. Akane asks if he could have a word with the two and requests them to come downstairs. He announces that they have put together a general plan to solve their issue. Nene walks downstairs with unresolved questions and wonders what Kou did during the severance.
Akane and Minamoto Teru explain that each supernatural has a deep connection with their origin in this town. Even after the severance, it is possible to open a path to the boundary through those. Akane assigns Kou and Nene to look into the Hell of Mirrors due to their familiarity with its representative, Mitsuba Sousuke. The next day, Kou comes to the school with Nene to look for things that Mitsuba may have had a strong bond with. When Nene asks if Kou had any ideas, Kou reiterates that the current third mystery is not the Mitsuba they knew, referring to when Tsukasa made a completely new supernatural with a part of Mitsuba. Kou admits to sometimes being confused about who Mitsuba is and stresses the possibility that Mitsuba truly is gone. He then suggests that they should go to ask different people.
Nene and Kou askes on of Mitsuba's old classmates, Yokoo. He states that he doesn't know much about Mitsuba, and instead refers Nene and Kou to his second year teacher. They ask the teacher in the faculty room, but he refuses to give up info about Mitsuba due to student confidentiality. Instead, he refers them to the members of the Photography Club. The members of the club didn't know much about Mitsuba, but one drew Nene and Kou a map leading to Mitsuba's grave. The two then went to the cemetery to search for Mitsuba's gravestone. Nene catches the attention of a woman passing by carrying heavy items. The woman loses her balance as her foot bends the wrong way. Kou and Nene run to tend to the woman, who askes them. The woman reveals herself as Mitsuba's mother.
Mrs. Mitsuba brings Kou and Nene to her apartment. Within the residence lies old photos of Mitsuba and his family and a shrine. Nene and Kou pay their respect to the shrine. Mrs. Mitsuba serves Nene and Kou some snacks. She says that it is the first time Mitsuba's friends have every visited. She asks the two what Mitsuba was like in school and wonders if Nene was the girlfriend of Mitsuba. Nene says no, but describes Mitsuba as a cute underclassman who had a cheeky side to him, referring to when she was called Radish-senpai. Mrs. Mitsuba sympathizes with her, stating that Mitsuba also called her a Carrot Monster Hag.
Nene says that Kou was the one who Mitsuba talked to the most. Kou says that he only went with him to take photos. With the small mention of pictures, Mrs. Mitsuba smiles and shows them some of her favorite pictures, all taken by Mitsuba. She also explains how Mitsuba adopted photography from his father's hobby. Mrs. Mitsuba had sometimes left the camera lying around the house, and somehow, Mitsuba had learned to use it. Soon, Mitsuba was earning photography awards.
Mrs. Mitsuba describes that Mitsuba has a very particular taste in fashion and nagged a lot about it. Every time she asked Mitsuba to take a photograph of her, Mitsuba would say no, saying that she should wear make-up and go to a beauty salon. Mrs. Mitsuba notes that Mitsuba took a specific interest in nature.
On his mother's birthday, Mitsuba promised to make curry for dinner. When Mrs. Mitsuba came home, the curry was there, but Mitsuba was nowhere in sight. Mitsuba left a note on the table, saying that he would be right back. The only missing ingredient in Mitsuba's curry was the potatoes. Mitsuba had forgotten to buy them, so he had left to buy them. That was how Mitsuba got into the accident.
Kou recalls a promise he made to Mitsuba, to develop the photos they took together. Sadly, they were never able to do it. Mrs. Mitsuba asks Nene and Kou to look at the pictures Mitsuba took, which were in his room. In the room, Nene sees the winter uniform and felt as if time had stopped. They looked through some old photos. Nene notices that Mitsuba barely took pictures of people. The only photos with people were of his mother. A photo slips out from the book. Nene picks it up and wonders what it is of.
Characters in Order of Appearance
- Yashiro Nene
- Minamoto Kou
- Mitsuba Sousuke (memory)
- Aoi Akane
- Hanako (depiction)
- Shinigami-sama (depiction)
- Tsuchigomori (depiction)
- Shijima Mei (depiction)
- Yako (depiction)
- Kako (depiction)
- Mirai (depiction)
- Yugi Tsukasa (memory)
- Members of Photography Club
- Mitsuba's Mom
- The team sets out to look for the deep connection within the mysteries to open a gateway into the boundaries.
- Akane assigns Kou and Nene to look for the deep connection of the third mystery.
- Kou and Nene meets the mother of Mitsuba at the cemetery.
- Mrs. Mitsuba says that her son disappeared after he went outside to get potatoes for the curry he was making.
- Nene finds an unknown picture in Mitsuba's photo album.