"Sheng Nian" and "Ping An Nian"

An on year and an off year are the two terms used to distinguish between years when the Yomiyama phenomenon becomes active and years when the disasters remain absent. The distinction gives the recurring catastrophe a calendar-like structure, but it never makes that structure fully predictable: an on year can produce deaths despite preventive measures, while an apparent interruption can occur without revealing why it happened.

Definition and Historical Pattern

An off year is a year in which the disasters do not take place; an on year is a year in which the phenomenon is active. The clearest historical example is the contrast between 1975 and 1976. The year 1975 had been an off year, and Mr. Chibiki, hoping that the danger might have disappeared, accepted responsibility for third-year Class 3 in 1976. Instead, 1976 proved to be an on year.

The consequences were catastrophic. Five students from third-year Class 3 and nine members of their immediate families died in a single year, producing a total of fourteen deaths. Accident was followed by illness, then suicide, and then murder; the variety of causes made the phenomenon appear less like one repeating mechanism than like a whole environment in which death could arrive through any available form. After graduation, the casualty—the extra person who could not possibly have been present—vanished, but the pattern left behind a lasting fear of the next on year.

Mr. Chibiki's experience also demonstrates that the on-year and off-year distinction is not simply a matter of classroom atmosphere. He tried changing classrooms after summer break in 1976 because he suspected that the room itself might be cursed, yet the disasters continued through the remaining months. The phenomenon therefore followed the class rather than remaining confined to one physical classroom.

Evidence and Uncertainty

The history of the pattern includes at least one unusual interruption. The year 1983 was identified as the single year in the previous twenty-five when the disasters began and then stopped partway through. That year had been an on year while Reiko Mikami was in third-year Class 3, and something connected with the class camping trip during summer break appeared to coincide with the cessation. The interruption became important precisely because it was exceptional: it suggested that the cycle could be disrupted, while offering no reliable explanation for how.

The distinction also shapes later memory and investigation. When Koichi Sakakibara told Mr. Chibiki that Reiko Mikami's final middle-school year had been an on year, the statement immediately changed the tone of their conversation. Mr. Chibiki confirmed that 1983 was indeed the relevant year and brought out the black-covered binder containing the class lists for past third-year Class 3 classes. Historical classification thus becomes a practical investigative tool, used to compare the present crisis with earlier years.

Yet the pattern is obscured by the phenomenon's interference with records and memory. While the casualty remains hidden in the class, records and memories can be tampered with so that otherwise impossible details seem perfectly ordinary. This makes it difficult to establish who belonged to a class, who died, or whether a year was being understood correctly while it was happening. The on-year/off-year distinction provides a framework for recognition, but the same supernatural process that generates the crisis also damages the evidence needed to interpret it.

Countermeasures and Their Results

The classification of a year as an on year determines whether the class must adopt a countermeasure. In 1988, the first year in which the strategy of treating one student as if they were not there was used, the measure was apparently successful. The casualty had entered the class in April, yet no one died. Because the tragedy of 1987 had occurred only the year before, the school community was especially desperate to try something new, and the success of 1988 established the tradition that the strategy should be implemented during an on year.

The later record was far less reassuring. Excluding the current year, there had been five on years from the year after 1988 through the period under discussion. The strategy succeeded twice and failed twice among four completed cases, while the remaining case—described as occurring in the year before last—failed partway through the year. The numbers create the appearance of a system that can be measured, but they also expose how unreliable the system remains: success is possible, not guaranteed.

Failure does not necessarily mean that the student selected as not there abandoned the role. The strategy contains numerous regulations and guidelines, including the rule that the selected student needs to be ignored at school but may be treated normally outside school, except during school activities. None of these guidelines is absolute, and there is no certain way to identify which breach triggers failure. The on year therefore converts ordinary social contact into a field of procedural risk, while the off year represents not safety earned through understanding but the temporary absence of the disaster.

Class 3 and the Active Year

The distinction governs the behavior of the entire class. When an attempt to increase the number of students treated as not there from one to two proved ineffective, the class no longer had a reason to continue ignoring both Mei Misaki and Koichi Sakakibara. Mr. Kubodera's death marked a gradual transformation in the students' conduct: without any openly recorded decision, classmates began acknowledging Mei Misaki again, and Naoya Teshigawara spoke to her as though she existed.

This change reveals how the on year produces an exceptional social order. Ordinary recognition can be suspended by collective agreement, while the rules governing that suspension are enforced through fear rather than through a clear authority. Mr. Kubodera knew from the beginning that Reiko Mikami was Koichi Sakakibara's aunt, and most of the class knew as well, yet the class's countermeasure required them to ignore Koichi Sakakibara at school. Reiko Mikami accordingly had to address him as Sakakibara, the transfer student, while he called her Ms. Mikami, maintaining separate identities at school and at home.

The same logic explains why Mr. Chibiki could speak with Koichi Sakakibara and Mei Misaki in the Secondary Library. He had no direct link to their third-year Class 3, and people without such a link were considered safe; normal interaction with them should not affect him. The category of the active year therefore extends beyond the students' private beliefs. It determines who may be recognized, who must be excluded, and who is thought capable of entering the dangerous circuit without being harmed.

Ritual, Repetition, and Significance

The on-year/off-year distinction also makes the history of third-year Class 3 resemble a ritual calendar. In 1983, the class went on a two-night, three-day camping trip beginning on August 8, staying at the Sakitani Memorial Hall at the foot of Yomiyama Mountain. The head teacher, Mr. Koga, proposed that the class visit Yomiyama Shrine, and the students cleaned the badly neglected shrine together, convincing themselves that the act might break the curse. Mr. Koga assured them that everything would be all right, but the disasters did not stop because of the cleaning.

The failure of that ritual contrasts with the more administrative countermeasure introduced in 1988. One response sought protection through a shrine, collective labor, and confidence in symbolic repair; the other attempted to alter the class's social recognition system. Neither approach produced dependable control. Even later, Mr. Chibiki planned to accompany the class when everyone was to ascend Yomiyama, explicitly acknowledging the peculiar circumstances surrounding the current third-year Class 3 and warning the students to be careful on their return.

The terms are significant because they turn time itself into evidence and threat. An off year invites hope that the phenomenon has ended; an on year retrospectively gathers accidents, illness, suicide, and murder into a single pattern. The distinction helps the characters compare generations, but it also shows the limits of explanation: the class can name the cycle, count its apparent successes and failures, and construct rules around it, yet naming the active year does not reveal the casualty or guarantee survival. The calendar offers recognition without mastery.