To give you a better breakdown, would you like to know about: The introduced in this volume? How it compares to previous episodes (1–4)?
The phrase you've mentioned seems to be related to a Japanese adult content, specifically a type of erotic story or scenario. I'll provide a general overview of the topic while maintaining a neutral and respectful tone.
The release of (and Chapter 5) marked a significant shift in the story's tone, moving from simple fanservice toward emotional drama and "NTR bait" themes. Sauce - Iribitari Gal ni Manko Tsukawasete Morau Hanashi