is a Japanese light novel series written by Shizuku Rei and illustrated by Rag Miwano. The series began publication under SB Creative's GA Bunko imprint in July 2023; four volumes have been released as of June 2026.

Plot

The series follows Haruma Amanai, a high school student and a fan of detective novels. One day, a new student named Momiji Reidō transfers to his class. While touring Momiji around the school, they discover that one of their classmates, Yamato Sasamura, had been murdered. The two decide to investigate Yamato's murder, taking advantage of Haruma's time travel powers and Momiji's immortality.

Characters

A high school student. He is interested in detective novels and runs his own literature study group, separate from the school's main Literature Club. He is an expert in kendo. He has the ability to go back in time by kissing.

A new student who transferred to Haruma's class. Despite appearances, she is actually 24 years old, being immortal. She also becomes a member of Haruma's literature group.

Publication The series is written by Shizuku Rei and illustrated by Rag Miwano. The novel was originally submitted to a competition run by SB Creative's GA Bunko imprint under the title , later being chosen as one of four Silver Award winners. Rei had an interest in mystery novels since junior high school, finding satisfaction in following mysteries and solving puzzles; they also cited the visual novel series Umineko When They Cry as an inspiration. They were inspired to write the novel after watching Evangelion: 3.0+1.0 Thrice Upon a Time; the novel's original title was a reference to Hikaru Utada's song "One Last Kiss", which was used in the film. SB Creative released the first volume on July 14, 2023; four volumes have been released as of June 2026.

Reception The series ranked highly in multiple surveys by the website Anime! Anime! on light novels that people wanted to see adapted into an anime, ranking 2nd for the first half of 2024, and 1st for the second half of 2024 and the first half of 2025. The first and second volumes received multiple awards from the Ranobe News Online Awards in 2023. The series was included in the 2024 edition of Kono Light Novel ga Sugoi!, ranking 12th in the paperback category and 8th in the new release category.

References

External links Light novel official website