From the Voice cast I have checked from Success, the cast is generally rather famous (The female lead being voiced by Ayako Kawasumi, The blonde hair girl being voiced by Marina Inoue and the older black haired woman being voiced by Naomi Shindo.).
Plot (spoilers maybe): You character is your typical drifter/average guy who meets a famous idol and dates her. And yes, you can get to second base (its not given a CERO C without a reason) with a girl.
And any notable ecchi moments in the game (I know there is no sex, but it should have a CERO C for a good reason) --- 'When in 21st century America, act like the freaking Romans 2,000 years ago. Random counter-productive brutality for the win!'