Ah, I’m super glad I can share this one on Hentairules, it’s a fine release, really, 196 pictures long, and full of excellent contents ^_^
Each chapter in Mokkai Shiyo? is a single story, with a simple canvas (featuring gentle teasing, an opportunity, and voilà! All of that with good enough vibes that we’ll smile quite often and like the characters), and pretty nicely drawn highschool girls having vaginal sex with very little censorship. There’ll be plenty of childhood friends, no drama or complications: simple as that 
I’ll let you see for yourselves, but I’ll insist, it’s totally worth a shot in my eyes
Side info, you may also be interested in Kimi wa Midara na Boku no Joou, an ecchi series, drawn by our present Yokoyari Mengo, with the infamous Okamoto Lynn (what? His manga series suck ass, let’s be honest) taking care of its scenario.
