Jun, a fifth grader in elementary school, is currently bullying at school. The father, Eugene, who discovered Jun ’s incident, said he would leave school and go exploring. The destination is the Geoscience Center in Garden City. Eugene, who is studying dinosaurs, has a business in the nearby fossil museum.
 He told Jun, who was a big fan of dinosaurs, "There used to be a Tyrannosaurus here." However, Eugene can be urgently requested and wait for a while with Center researcher George. Jun is taken to George to see a 500 meter underground cave.
So Jun hears a voice saying "Take me out" from nowhere. Jun then stole George's eyes and entered the underground world alone.
If you infiltrate a crack in the wall, you will encounter a strange creature. It was a dinosaur, Pucci, shorter than humans. Moreover, Pucci had a mysterious power to talk directly with his heart.
Jun is taken to Pucci and comes to the underground dinosaur world where the same light and forest as the earth spreads. Jun entered the vent that sent air into the basement.
There is a dinosaur village ahead of them, and they are surprised by the dinosaurs who see humans for the first time, but they are accepted by the forgiveness of Elder Kera.

Jun is taken to school by Pucci. So I met Tyrannosaurus Titi.
Titi was perceived as ferocious and mean. Jun digs a pitfall and tries to give Titi to the barking Pucci. However, Jun actually talks to Titi and realizes that he is not.
However, they fall into a deep hole different from the pitfalls. At the bottom of the hole, Jun learns the true feelings that Titi wants to get along with. Then, carrying Titi who fears the hole, climbs up and succeeds in escaping.
Jun was accepted by everyone in this incident. That night, Jun hears a horrible voice. It was from the Giants who resonated from the sea and left a huge figure from ancient times, unlike the Pucci and the Small.

One day, Jun learns that the vents from the ground will be filled with Mountain Shell's construction to mine shale oil.
Jun suggests that if a giant bone is placed in the cave, a large-scale investigation will begin and the construction will have to be interrupted. Although it is objected to go to a giant village, Jun decides to make a squid and cross the sea.
In the middle of the night, Jun tries to go alone, and Pucci, and Pucci ’s sister, Lara, joins. In addition, Titi who refused to go once scared will follow. The four cross the sea with squid. The group who arrived at the Giant graveyard with the mysterious power of Lara escapes from the attacking Giants and crosses the sea again to return to the small village.

Jun returns to the ground with a Giant bone. And when I put my bone in the cave, an illegal blast of Mountain Shell took place, and Jun was fainted by the impact. I noticed it was a hospital room. It was unconscious for 3 days.
I think everything was a dream, but Jun's pocket had a real dinosaur scale and claws. And the bones of dinosaurs were discovered from the tunnel, and they learned that adults including Eugene were making a fuss.
Classmates who were bullying entangled with Jun who returns to school after a while.
But it was no longer scary for Jun, who had a great adventure with Pucci. The words that were said when I broke up with Pucci were obsessed with Jun.
"Come back, Jun"


Jun Mount (12)
A boy of fifth grade in elementary school. The results are good but not top class. Recently I was being bullied by my classmates and I was betrayed by a friend who should have been good friends until last year. It is overlooked by the sassy little sister. It was once a large dinosaur fan by the influence of his father.

Eugene Mount (36)
Jun's father. I am studying dinosaurs as a professor of Sanyo University and an ancient biologist. Suddenly, he left school and invited him to go to the Tono Geoscience Center in Gifu Prefecture. Jun accepts his father's invitation, thinking that he may have noticed his or her abnormality.

Olca Mount (9)
Jun's sister. Fourth grader. A popular person in the school with a character that says things clearly. However, Jun's older brother feels such a younger sister like a mass of sassy.

Ezuca Mount (35)
Jun's mother. I notice the unusual thing about Jun who is bullying and consult with my husband Eugene.

Jun's classmate. I was supposed to be a close friend until May of the sixth grade, but one day I suddenly went to the side of bullying Jun.

Jun's classmate and one of Shinichi's entourage. I agree with Akira and tease Jun.

Researcher at the Geoscience Center. Medium meat Medium tall and quite normal person. Wearing thick glasses, the head is bald to the far back of the forehead. Jun's father, Eugene, asked to take him out underground and guide him.