Yuzuki, a virgin who was studying with videos and books to succeed in her first sex after finally getting a girlfriend. Then, J〇's sister invites her, saying, "Will you practice with me?" She is taught a forced kiss, but the lecture escalates more and more. Losing her reason to her sister's completely grown-up body, she sucks on her raw pussy without hesitation, and it develops into forbidden incest sex...! *the recorded content may vary depending on the distribution method.