For anyone who wants to read isekai story with faster story pace, a real goal, lots of actions, then I'm sorry to say, this isn't the manga for you.
This manga is based on an R-15 web-novel about slow life and wish-fulfillment in an isekai setting. There is no demon lord to kill, no evil master mind hellbent on ruling the entire world (or destroying it for whatever weird reasons), no revenge plot that span through the entire realm, nada. It's about MC doing his daily life in isekai alongside his women, with sex on top. Nothing more.
Granted, since the novel is not rated R-18 or above, the sex scene in the web novel was not as detailed as the manga's depiction. For instance, this chapter was about ten paragraph or twelve in the web novel. It's probably just the mangaka's preference and a way to help sell the manga.
Not that I'm complaining since I came here knowing what to expect. In fact, I found this chapter to be much much better than the actual webnovel chapter because the feelings between the two were more pronounced. For instance, Roxanne muttering to herself after Michio lied to her about persons close to each other use their body to wash each other in his homeland, Michio taking the initiative to 'wash' Roxanne after she smothered him with her breasts, and the kiss at the end of this chapter weren't exist in the webnovel. The bath scene on the webnovel instead ended with Michio's thought before Roxanne kissed him in the manga.
There is a good reason why many people here think having Roxanne was enough. even with the 'harem' at the title. And that's the because the manga added extra scenes and details like that.
So if you're expecting something more than that, then I suggest you to read something else instead.