[Machine Translation] The secret of immortal girls. The light that leaks out and the shadow of a needle. I'll be a great detective! What? What do you mean Shihon-chan might die? Eh? Shihon-chan's head is gone? It seems that Shihon-chan's headless torso was found in the meditation room. But, it is possible to reconnect the head within 48 hours, right? What? The head was not found? Did someone hide it? You don't know? Murder is not uncommon. There is always at least one murderer in a school. Killing is fine, but cutting off the head and hiding it is a taboo. If you do that, you will not be able to revive. I can't believe that Shihon-chan had such a grudge against someone that she would be killed in a way that would prevent her from being revived. If we don't somehow find the head within two days, Shihon-chan will really die! I will never accept that reality! Now is not the time to be in shock or cry! There must be something I can do! 'I've never done such a thing, but... Wow, me! I will definitely find Shihon-chan's head! I'll play detective! A boarding school isolated from the outside world. The school is a boarding school isolated from the outside world, where immortal girls live there. They spend the same amount of time as adults, growing younger and younger until they become babies, and then growing older and younger again until they become adults again. There is only one condition for graduation from the school. The only condition for graduation from the school is to be judged a genius by someone who is observing them from the outside. The moment this judgment is made, the girl is allowed to graduate and disappear from the school. The immortal girls' peaceful school life is thrown into chaos by a murder. Why are the girls immortal? Why do they grow up and become young? How much time has passed since they were trapped in the academy? How can they be decapitated and still come back to life? What happens to the girls who don't become geniuses? What is going on in the outside world? Why is there only a girl? Where are the men? What is it to die? What is life? What is life? What is life for? The key to the case is a needle. A binding needle. Stick needles. Sewing needles. Silk needles. Knitting needles. Gauze needles. Futon needles. Clothes needles. Fishing hooks. Waiting hooks. t-pins. Leather triangle needle. Led by needles, immortal girls die. ( CERO Age rating: to be determined )