I'm not sure where the images came from but that series is sengoku rance. Its origins are a H-game so that could either be an offical manga or doujinshi.

Amano Suki Darake vol2
Volume 1 has a bunch more

I believe that manga is based on "Rance Quest", actually. As there is an ENF CG with Kanami (the girl in the doujin/manga) wearing that exact "outfit" in-game.

Rance Quest Chapter Search
 

I also think the images are from the manga, "Rance Quest".
There seems to 4 volumes of the manga. I've only seen volumes 3-4 online, and the scene is not in those volumes.

The only other lead I have is that the images are drawn by artist:shirane taito.
The only chapter of Rance Quest I can find online by the artist is the chapter, Kanami Sex Scene.
Attachment 8459982
(Warning to anyone who might also look up the artist, most of the artist's works involves lolis)

Manga6?
 

Does anybody know the names of these manga?

Boku wa Tomodachi vol5
the best

More Boku wa Tomodachi

Reply to Sporzem
 

The sixth image is from No Pan Seitokaichou

TOGAMI Shin's Momoiro Heiki Spin

Guglielmo stuff from Comiket 90 which was last weekend

Title for those who are interested in the full version: 保健体育実習授業～女の子の身体のしくみ編～