Around 8 years old, Kuroo moved next door to Kenma with his family, consisted of his father and grandparents. Whenever he was left alone, he would come to Kenma's house instead. He was noted to be more shy and withdrawn than Kenma, so the two introverts had a difficult time getting to know each other.
Initially, Kenma and Kuroo just played video games. One day, Kenma asked him if there's anything he would like the play. Kuroo took this opportunity and introduced volleyball to Kenma. The two ended up playing volleyball outside and grew familiar with each other. While heading home, Kuroo, not wanting to go to a new place alone, invited Kenma to come to a volleyball training camp that weekend. Kuroo and Kenma went to the training camp. There, they encountered a young Nekomata, who told the two that it's important to experience the joy of playing. Kuroo was inspired by Nekomata's words and became more proactive. He joined a volleyball team and made new friends at school. Since there were no volleyball players in the neighborhood, Kuroo would still drop by Kenma's house to watch videos of professional volleyball matches together. He would mimick moves he saw, later showing them to Kenma. When he saw Kenma's interest in volleyball tactics, he urged his friend to become a setter, citing it as a perfect position for a strategist and not having to move around much. He and Kenma went to the same middle and high school.
Later, Kuroo convinced Kenma to join their junior high's volleyball team and they have played volleyball together since then. When Kenma was having trouble fitting into the team in his first year of high school, Kuroo encouraged him to stay by telling Kenma he is a big asset to the team.