I just found this manga in E-Hentai, and so far there's 5 chapters, with some good process and giant girls. The artist is Yatera Keita and the title is Onideka (if I got the info right. I might be wrong about this). If anyone knows more info about this manga or can find more chapters, please feel free to add them here.
Link to the manga: http://g.e-hentai.org/g/967055/5d167c38ee/