WNZ-467 - Real sister hot spring trip, couldn't hold back anymore

Mifuyu, the quiet but popular literary girl in class, still remembers a promise she made to her brother when they were young. During their trip, she gathers the courage to kiss him but can't find the words to confess. Seeing her innocent face and petite, undeveloped body, he finally gives in to his desires and begins to ravage his fragile sister's tight, little slit.