Shitsuren Kashima No Natsuyasumi (“Heart-Broken Kashima’s Summer Vacation”) [English], an hentai doujinshi parodying the Kantai Collection game, by Kekocha (circle Chibikko Kingdom)
Sad, sad Kashima. She’s in love with her Admiral, but he chose another shipgirl. So, she goes alone to the beach, lets a good-looking hunk seduce her, they have sex, more sex, a lot more sex, and more sex after that, finally she’s doing okay by the looks of it ┐( ̄ヮ ̄)┌
So, yeah, that wasn’t complex at all. But that was’t necessary at all. Because, oh boy, the drawings were FUCKING AWESOME, fapping gold!!
Enough said, I hope you’ll find it to your tastes
My great thanks go to Biribiri, Axalon, Megaton and Anon!
By the same artist, I also share Datte Suki Damon and Kagamiya-san No Kannouteki Na Oshigoto. You may also need a certain clarification, search for “Kekocha” in this page.
And now, the download & gallery links 
Open the Complete Pictures Gallery
Download the Free Hentai Manga in a Zip file
(126 MB, 39 pictures, English)
Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2 – or – Zip Mirror #3
–
Smaller version incoming!
As of usual when ☑ the images are in high enough resolution and ☑ the archive is quite big for its number of pictures, and ☑ it offers a significant gain, and ☑ I have enough time to do it, if it may help, I’m offering you a smaller version, in which I resized the images, here from 3590 px to lower-standard 1600 px resolution.
The zip shrank from 126 MB to 21 MB.
Personally, I prefer it for reading, and it takes less disk space.
Download links, Zip: Mirror #1 – or – Mirror #2 – or – Mirror #3 – or – Mirror #4
Artificial genital organ of an anthropomorphic naval vessel has “learned the taste of semen”.
Possible future outcome(s): (1) Terminator – Rise Of The Machines, (2) The beginning of The MATRIX.
OR we go with (3):

Well, I don’t know if I’d call that happy sex. The playboy guy doing her is a virgin hunter and his two pals referred to Kashima out of earshot as ‘fuggly’, thereby combining inherited blindness with the learned behavior of being complete assholes. I wouldn’t mind if a tactical nuclear strike improved the gene pool by removing these three douche bags. Sure, it’s not likely to happen in a sequel, but I can dream.
Male Character’s internal dialogue confirms your speculation. Luckily for him (and by extension, his “friends”), Kashima couldn’t tune in to his inner thoughts, otherwise, it would be an open-and-shut plus justifiable case of:

They were talking about another girl, they haven’t met Kashima before. It’s an off-scene dialogue between them about a different girl.
Also, @Oliver, “My great thanks go to Biribiri, Axalon and Megaton!”… and anon.
Anon?
Woops? Didn’t see that in the credits area, my bad!
Updating the post
Sorry, most the times when there’s no credits for commissioners, it means it was anonymous.
You’ll need a couple of these if you read this stuff:
-Sex on the beach recipe-
1 shot of Vodka
1 shot of Peach Schnapps
3oz (150ml) of cranberry juice
3oz (150ml) of orange juice