In eighth grade, he transferred to Bowling Green Middle School in Kentucky and led the team to win the first state championship. In June of the same year, Harmon was selected to the U 16 National Youth Team, averaging 1 1.4 points and 3.2 assists per game, helping the team win the gold medal. Harmon transferred to Adele County High School in the new season due to the change of coach in Pauling Green.
In his sophomore year, Amon transferred to Marshall County High School in Kentucky. Harmon was suspended for one year for violating the transfer rules, so he joined the team in Scottsdale, Arizona as a sophomore. After the suspension, he returned to Marshall County High School where he once attended, averaging 25.4 points and 5.2 assists per game.
As a four-star guard, Harmon received many invitations from strong teams and was eventually recruited by West Kentucky. In addition to excellent offensive and singles skills, Harmon also showed top-level three-point shooting ability, and his shooting percentage was also very impressive. His passing vision is very good, with a big start and a fast pace. In the game, it is often seen that he divides a beautiful pass after the explosion, which can help teammates and teams score points. As for weakness, 19-year-old Harmon is only 65430.