都会から瑞浪市に引っ越してきたばかりの女子高生の釜戸るい(17歳)は、都会の生活を諦めきれず、いつもスマホばかり見ていて、SNSの裏垢で毒づく毎日。
登校中スマホを見ながら川沿いを歩いていると、何かにぶつかり土手を転げ落ちるるい。
頭に絆創膏、壊れたメガネをテープで固定して化石博物館の課外授業に出るが、やっぱりスマホばかり見てつまらなそうにしている。
帰り道、スマホを博物館に忘れたことに気づき取りに行った際、ひょんなことからクリーニング中の化石「パレオパラドキシア」の全身骨格を見つける。
そこからるいは、とても不思議な体験をする…

Rui Kamado (17 years old), a high school girl who just moved to Mizunami City from the big city, cannot give up her big city ways and is always looking at her smartphone and immersing herself on her social networking accounts.
On her way to school, while walking along the river looking at her phone, Rui bumps into something and falls down the riverbank.
She puts a bandage on her head, tapes up her broken glasses and goes to an extracurricular class at the fossil museum, but she is still looking at her phone and seems bored.
On her way home, she realizes that she left her phone at the museum and goes to retrieve it, where she finds a fossil skeleton of a ""paleoparadoxia"" that is being cleaned.
From there, Rui has a very strange experience..."