i finally confessed to the classmate i had a crush on for a long time and succeeded in making her my girlfriend. she is a beautiful girl who is very popular even in school. i was at the peak of happiness beyond compare. however, suddenly, my sister "kurara" told me that she had something important to tell me. my sister suddenly demanded that i date her. actually, deep down, i thought my sister had a great figure, was sexy, and very cute, and it's true that i had forbidden fantasies... my heart shaken by my sister's honest feelings, i made a certain decision... monopolizing my too cute sister's pure body!! a forbidden erotic kyun & love experience unfolded between brother and sister on the verge of their limits!! "big brother... i'll do it for you... ◆"