Complex sentence: On his first day at AGHS, he reunites with his childhood friend Yuki Jojima, and Gentaro makes it his objective to befriend loner Kengo Utahoshi, who goes out of his way to avoid him.
Split into simpler sentences: On his first day at AGHS, he reunites with his childhood friend Yuki Jojima. After this reunion, Gentaro makes it his objective to befriend loner Kengo Utahoshi, who goes out of his way to avoid him.