If you liked the Nozoki Ana manga, the Anime-Planet community thinks you'd like:
Every day after school, the quiet and introverted student Kurosawa goes into the empty girls bathroom and "relieves himself". Besides this extremely odd ritual, Kurosawa also has a thirst for justice and a judgmental attitude towards his classmates. Upon seeing the bullying of an awkward girl in his class by two of the "popular" girls, he decides to bring justice to the bullies the only way he knows how. His plan for revenge goes "just as planned" until met by an unsuspected accomplice.
Nozoki Ana and Onani Master Kurosawa are similar in the aspect that they both have a serious plot based around the subject of sex and masturbation respectively. Both play with the aspects of human emotion, interaction and serious character development. In both there are characters who aren't quite what they seem to be. If you like one of these, I can almost garuntee that you will like the other.
Both manga have a similarity, main male character dragged into some weird relationship by force. While in Nozoki Ana main female character forced the main lead to peep on his sexual life by blackmailing him, on the other hand in Velvet Kiss the step mother of the female lead character who pulled the strings to be friend with her daughter only to achieve her greedy objective. But in both story both male and female leads fall in love with eachother eventually. [and both contains sexual scenes.]
While performing a delivery to a beautiful woman’s apartment one night, twenty-five-year-old Kimijima finds himself in the arms – and loins – of his customer, the newly-divorced Kana-san. The next morning Kimijima heads to an interview, only to find that one of his interviewers is Kana-san herself! Now, Kimijima must work hard at his new job while having ample sexual encounters with not only Kana, but hostesses, fellow interviewees and old friends (at least in his dreams) - to say the least! However, to make things more complicated, Kimijima finds himself falling for Kana...