A portal to another dimension is suddenly discovered. What spread out beyond the nondescript door was a parallel world with a history different from this one. This year marks 50 years since the world behind the door was named "PORTAL" and observations of its interior began. "PORTAL-X" is a program that has been broadcast for many years with the aim of utilizing the failure cases of various portals in our society.

Kaif is a new program director who reports on all sorts of parallel worlds, and Luna is a program cameraman. The various parallel worlds and portals that the two of them cover are all worlds where people have made wrong choices at turning points in history and have fallen into irreversible situations. What is shown on camera are food shortages, a world where immortality has been achieved, a society that has not achieved true diversity, an extremely low birthrate, and a world that relies entirely on luck.

突然发现了通往异次元的大门“门户”。在没有任何变哲的门对面蔓延的是与这个世界不同的历史的并行世界。门后的世界被命名为“Portal”，自开始进行内部观察以来，今年已经50年了。“PORTAL-X”是一个多年来一直在播放的节目，目的是将每个门户网站的失败案例应用到我们的社会中。Kaif（柄本Tokio饰）是报道所有平行世界的新人节目导演，以及节目摄影师Luna（伊藤万理华饰）。两人采访的各种并行世界门户网站都是在历史转折点上做出错误选择，陷入无法挽回的状况的世界。摄像机中看到的是粮食短缺、永生的世界、无法获得真正多样性的社会、极度出生率低、依赖运气的世界。凯夫和露娜通过采访，感受到了什么，传达了什么？随着采访的不断重复，变得越来越清楚的是这个...