To answer OP Question, no such translation exist, that is the only game in the series not to be translated or localized outside Japan till this day. Maybe seek someone who knows Japanese or a guide on how to get started. Usually someone writes such things.
Now to clear up somethings.
First of all, it has a genre, is called rail shooter, much like house of the dead or sin and punishment.
Second, it's a special gun that shoots Pheromone shots, giving the girls instant ecstasy so they will leave you alone.
Third, there is more "perverted" Games out there, like dead or alive, senran kagura or Valkyrie drive where you actually get to look at the character model from different angles, dress them up and take pictures of them to share with people. Sure in this game you do get costumes to put them in, but no where near as skimpy or revealing as senran kagura or dead or alive, those are considered gavure and the actress in them called "Gravure idols."
This game has a story that is simply supposed to be amusing, it's intentional "Tongue and Cheek Humor" that make reference to pop culture or is over the top. It's not supposed to be taken seriously. It's a honest game, it doesn't make excuses as to why the characters interact the way they do. No one invited them to a island on vacation to populate the area with attractive women with alternative motive. (Dead or alive extreme) No one is transforming into combat weapons from ecstasy to cure a virus (Valkyrie drive) It's a rail shooter that doesn't have dark, depressing, and serious tones.
I get that perhaps fan service will always be controversial, but the fact that rail shooter genre of games on modern systems are lacking about as much as volley ball games (yeah Dead or alive extreme may just be the only one) some are willing to look past the that part of the game and just enjoy the game for what it is.