When 17-year-old Makoto Konno gains the ability to, quite literally, “leap” backwards through time, she immediately sets about improving her grades and preventing personal mishaps. However, she soon realises that changing the past isn’t as simple as it seems, and eventually, will have to rely on her new powers to shape the future of herself and her friends.

Cyborg detective Batou is assigned to investigate a series of murders committed by gynoids—doll-like cyborgs, which all malfunctioned, killed, then self-destructed afterwards. The brains of the gynoids initialize in order to protect their manufacturer’s software, but in one gynoid, which Batou himself neutralized, one file remains: a voice speaking the phrase “Help me.”

In the aftermath of the most devastating conflict mankind had ever experienced, the tiny island of Shikotan became part of the Sakhalin Oblast… and on the unhealed border in this remote corner of the world, friendship among children from two different countries timidly blossomed, striving to overcome language barriers and the waves of history. Inspired by true events.