The kind older sister indulged her young brother. Because he was spoiled since he was young, his rebellious personality meant that whenever he wanted something, he would get it, leaving the older sister with no choice but to deal with his many strange requests. But this time, the little boy asked for something no one would have thought of, which was to have sex with his older sister. However, her loving nature towards her younger brother made the older sister think a little and she agreed, but on the condition that it be kept a secret.