During a VESPER staff review of Mahoro's life and activities following her entry into civilian life, a letter from Mahoro is read to the assembled officers. In it, she describes taking part in a "summer vacation group research trip" to explore the notorious "nine mysteries" of Hiryu School 4. Seven of these are generally acknowledged to be no more than standard rumors typical of any school; the remaining two, however, have not been as easy to put to rest. Of course what Suguru, Kiyomi and Toshiya don't know is that all through, the three girls, minus Mahoro, are playing them, as part and parcel of their own "human response to stress" research project. But seek, and ye shall find: it does not take much to send them running frantically through the school to get away from "red-haired Ando", according to legend, a girl who fell to her death from the school roof years ago and has been haunting the halls at night ever since. Mahoro herself is in on the joke, though she plays along. The twist, however, comes when, after becoming separated from the group, she comes across the real Ando, a ghost or spirit trapped in the school until she can confess her love to a boy whose own spirit is trapped in another part of the building. Reunited by Mahoro, the two ghosts, now freed - and together - disappear, and the letter concludes.
Suguru doit se rendre ce soir à l'école en compagnie de Toshiya et de Kiyoni afin d'enquêter sur les "mystères" de l'école, et notamment sur l'existence d'un fantôme aux cheveux d'un rouge sang. Mahoro, qui ne croit pas aux fantômes, décide de les accompagner...
해수욕장에서 일어난 소동에 대한 보고가 이루어지고 있는 베스퍼 본부에 마호로로부터 한 통의 편지가 도착했다.
그 편지에 의하면, 어느 날 마호로는 스구루의 같은 반 아이들과 여름방학 그룹 연구 ‘히류우 제4중학교의 9대 불가사의를 밝혀라’라는 프로젝트에 참여하여 아무도 없는 밤학교에서 유령 탐색을 실시하던 중 8번째 불가사의인 ‘붉은 털의 안도씨’에 관해 조사를 개시하고 싶다는 내용이였는데…
Durante una revisión del personal de VESPER sobre la vida y las actividades de Mahoro luego de su ingreso a la vida civil, se lee una carta de Mahoro a los oficiales reunidos. En él, describe su participación en un "viaje de investigación grupal de vacaciones de verano" para explorar los notorios "nueve misterios" de la Escuela Hiryu 4. Generalmente se reconoce que siete de estos no son más que rumores estándar típicos de cualquier escuela; los dos restantes, sin embargo, no han sido tan fáciles de poner a descansar. Por supuesto, lo que Suguru, Kiyomi y Toshiya no saben es que, en todo momento, las tres chicas, menos Mahoro, las están interpretando, como parte integrante de su propio proyecto de investigación de "respuesta humana al estrés".
