is a Japanese light novel series written by Yū Omiya and illustrated by Eeru. It was originally serialized as a web novel on the websites Shōsetsuka ni Narō and Kakuyomu from December 2017 to December 2021. It was later published by Kadokawa Shoten under their Kadokawa Sneaker Bunko imprint, with eight volumes being published between December 2019 and November 2023; an additional volume was released digitally in October 2024. A manga adaptation illustrated by Yōhei Kazawa began serialization in November 2021, and has been compiled into six tankōbon volumes as of August 2025.
Plot
The series follows Yūta Hasegawa, a university student who recently broke up with his girlfriend after she cheated on him. Feeling alone as Christmas approached, he encounters Mayu Shinohara, who is wearing a Santa costume. Feeling a connection, he and Mayu start to hang out.
Characters
A second-year university student who recently broke up with his girlfriend. He is a basketball player and belongs to a circle of friends named "Start".
A first-year university student who goes to the same school as Yūta. He initially encountered her on Christmas Eve as she was distributing flyers while wearing a Santa costume. They form a relationship and she frequently visits his place.
Yūta's friend and a second-year university student at their school.
Yūta's ex-girlfriend, who broke up with him shortly before Christmas.
Publication Light novel The series is written by Yū Omiya, who originally posted it as a web novel on the websites Shōsetsuka ni Narō and Kakuyomu from December 23, 2017 to December 7, 2021. Kadokawa Shoten later began publishing it as a light novel series with illustrations by Eeru under their Kadokawa Sneaker Bunko imprint, releasing eight volumes between December 1, 2019 and November 1, 2023. An additional volume featuring an epilogue and side stories was released digitally on October 1, 2024. The novels are licensed in English by Seven Seas Entertainment.
Manga A manga adaptation illustrated by Yōhei Kazawa began serialization on the ComicWalker and Niconico Seiga services under Kadokawa Shoten's Shōnen Ace Plus brand on November 26, 2021, with the series being compiled into six tankōbon volumes as of August 2025. A voiced comic video of the series was posted on YouTube in December 2022. The manga is also licensed in English by Seven Seas Entertainment.
Reception In September 2024, Omiya reported on his personal Twitter account that the series had sold over 400,000 copies.
References
External links Light novel official website at Shōsetsuka ni Narō Light novel official website at Kakuyomu Light novel official website at Kadokawa Sneaker Bunko Manga official website at ComicWalker