Godou Kusunagi is Shizuka's brother. Shizuka appears to care for her brother but be extremely exasperated by his actions, especially the fact he's such a ladykiller, and doesn't even know it. Sometimes acts as if 'she' is the elder sibling and Godou is the foolish younger brother. It also sometimes seems as if there's a certain amount of jealousy in how she reacts to the various girls around her brother, suggesting that she may have a brother complex. Also it appears that Shizuka is the only person that Godou truly fears above all else.
In the early volume, Shizuka showed respect toward Yuri because she was her senpai from the same club, however, as Yuri started to getting closer toward her brother, Shizuka is becoming more wary of her.