GVG-305 Real sex education of older sister Yuma Kouda

Yuma, who lost her mother 10 years ago, lives with her father and younger brother Dome. One day, Dome ends up dreaming. Yuma, who accidentally discovers it, consults with her father, but is lightly treated as "I'm a boy, so I'm relieved." Yuma decides to give sex education to Dome with her own body in order to teach her sexual knowledge.