The episode begins with a short flashback to when Loki, Balder and Thor were children, making a promise to always be together.
It is winter in the Hakoniwa. In the library, Balder helps Yui to take a book that was beyond her reach. While Yui and Balder discuss how to hold a cultural festival in winter, they are mobbed by a group of students. After Yui helps Balder get away from the crowd, he asks if she is alright. Yui asks him the same question before remembering he can’t get hurt. Because Balder’s mother loved him so much, in order to protect him from death, she made agreements with all things in creation, and that’s why no one can hurt him. Everything that might cause him harm avoids him, but Balder can hurt himself if he trips and falls. Balder wonders why being around him doesn’t affect Yui, even though as the god of light, he subconsciously charms everyone around him. He holds Yui’s hand, telling her she is special and he is comfortable by her side. Unbeknownst to them, they were seen by Loki.
Yui proposes that they hold a Christmas market instead. They can set up booths in the courtyard and decorate the trees there to turn them into Christmas trees. While discussing how they should pick groups for the booths, Yui suggests dividing them up by their mythology’s nation of origin. This meant that Yui would be working with Takeru and Tsukito.
While walking with Yui, Balder asks why she suggested an arrangement that would separate them and says that as punishment, she will dine with him every day, from now on. Takeru tells Yui to quit loafing around since they need to discuss their booth, but Balder excuses her by saying they need to go and assist the teacher. Balder and Yui meet Loki, who glares at Yui after Balder says he has promised to eat with Yui every day. Balder wonders what to do, since Loki has prepared his favourite barbecue, and in the end decides Yui should just have barbecue with them, to Loki’s displeasure.
During the barbecue Loki serves only vegetables to Yui and is shocked when Balder feeds Yui the meat. He asks Yui what she has done to Balder, and do Japanese gods have some weird power. Loki gets another shock after being told Yui is human and is here to represent humanity. He glares at Yui, saying now he wants to keep Balder and her apart even more.
Loki repeatedly gets in the way of Balder being alone with Yui. Yui overhears Balder angrily asking what Loki thinks he is doing, acting this way towards Yui. Balder tells Loki not to disappoint him any further. Loki tries to walk off but Balder follows him and wants to know what is bothering him. Loki asks him why he cares so much about that human and Balder replies that Yui is special. As he spent time with her, he experienced her sincerity, earnestness and kindness. Being with her makes his heart dance and warms his heart. Loki reminds him that they had promised to always be together, along with Thor, and Balder replies that he remembers.
Thor finds Yui and tells her how Balder, Loki, and him have always been together. Because Loki was extremely mischievous, he was ostracized and left alone. Even Balder felt alone, despite being surrounded by people due to his power to attract others.. But opposites attract, so the two were drawn to each other and became friends. They always did everything together and Thor was always there, watching them. Loki and Balder share a special bond that not even Thor can interfere with.
Loki calls out to Yui and offers to help with the box of decorations she is carrying. He apologizes for teasing her the other day. He tells her Balder scolded him, saying that he has no idea how hard it is for a mortal like Yui to live in this strange place. Yui says that at first she was bewildered but now she enjoys the time they spend together and hopes they’ll have the best graduation together and create wonderful memories together. Loki drops the box and pulls Yui aside, saying in that case the two of them should make some special memories together until they graduate. To his surprise his words make Yui happy and she asks if that means he’ll try to graduate with them. Balder sees the two of them speaking from a window and after noticing how happily Yui is smiling at Loki he asks ‘Why?’.
During the lighting ceremony of the Christmas market Tsukito notices that Yui is nowhere to be seen. She is speaking with Balder, who asks her how she feels about him. He asks if it is because she loves Loki, much to Yui’s confusion. Balder says that he understands, and in that case he’ll make it so that she can see only him. He is about to kiss Yui but Loki separates them. Loki tells Balder to look only at him and that he belongs to him.