One day, Eric, who is in the 9th grade, decided to drink the water on the way to gym class to get himself ready for the day ahead. While not knowing that this water makes people younger, the 15-year-old initially has not been affected while in the changeroom.
During warmup, Eric began sweating more than normal, and, as he sweat, he felt that he was getting smaller. The shrinking didn't affect him until it was time for basketball. At that point, Eric constantly trips on his own clothes and, instead of playing the sport, he has to hold his own shorts up to prevent embarassment.
After gym class, Eric immediately went to the school bathroom, and what he saw in the mirror was a ten-year-old boy, only to see that he is the ten-year-old in the mirror. Shocked about his reflection, Eric made an attempt to escape the school, only to get caught by one of the teachers. He told Eric that he was in the wrong building while being taken to the vice principal's office.
As Eric arrived to the office, he told the vice principal that the fountain near the parking lot must have had something to do with the reversion to the age of ten. Despite what he said, the vice principal phoned the elementary school about Eric's sudden regression, and told him to go to the elementary school's main office.
When Eric entered the elementary school, the VP of the high school had already enrolled Eric to the fifth grade, and was told that recess had just started. During recess, Eric was an outcast, ignored by other kids. When it was time for class to resume, Eric suddenly began acting up, doing things such as interuppting the teacher, annoying other students, and talking back after given many warnings. Little did anyone at the elementary school know, Eric was behaving terribly because he has not completely settled in to his younger body. At that point, it was clear that Eric's life has taken a turn for the worse.
As soon as Eric returns home, his parents told him about what's been happening at school. They were told about the fountain at the high school making him a kid and, more importantly, how he has been behaving at school. At the end of the lengthy lecture, Eric's parents decided to ground him for a month, and give him daily chores that he must do before even thinking about his free time.
As days go by, Eric finally settled in to his younger body, and behaved better at school. Despite that, the grounding did not reduce. Also, new rules have been established at Eric's house, including an earlier bedtime, having do to all chores before having friends over or watching TV, and no longer allowed to leave the house except for school, even when he turns 15 again.
One day, Eric was cleaning the bathroom when he looked at his reflection, still seeing a ten-year-old boy. He looks at his reflection and asks himself "Is this my life right now?".