Eleven year old Yusuke and his classmates are camping in a woods when suddenly they see a bright light streak over the treetops and into the woods. The boys take off into the woods towards the light. There in the ground, growing, they find a small round metallic object. Just as Yusuke reaches to touch it, the mysterious object up pops a set of eyes and the object says;
"I am Tetra,I meet Yusuke". Startled Yusuke replies "Your name is Tetra? Cool!"
Tetra is kept from adult eyes in Yusuke's closet. Tetra creates wonderful gadgets using "never-seen-before" technology. It would appear Tetra was designed with artificial intelligence. But where did Tetra come from and what is its purpose? As the relationship grows between Yusuke and Tatra, these questions are answered.