Complex sentence: Yoshida often worries about concealing his romantic relationship with Satou and protests when Satou is too affectionate at school, and he also tries to rein in some of Satou's sadistic tendencies toward others.
Split into simpler sentences: Yoshida often worries about concealing his romantic relationship with Satou and protests when Satou is too affectionate at school. He also tries to rein in some of Satou's sadistic tendencies toward others.