Otona wo Shiritai Onna Tomodachi

Tatsuro Saruwatari is a 20-year-old college student. While others around him are enjoying the college life, he is content with being alone. Because he has a noble hobby… watching "adult videos." He tells himself, "I don't need a girlfriend. I have porn." One day, however, his classmate and gal pal, Eimi Kaniko, catches him jerking off to porn! Tatsuro thought that this might be the end of their friendship, but she says something even more shocking. She asks him, "Wow, can I watch AV with you?" Now he's watching all kinds of porn with a naive girl, while trying not to give in to immoral impulses! (Source: Kadokawa, translated)