"Iribitari ga ni manko tsukawasete morau hanashi" can be translated to English as:
Or, in a more natural English phrasing:
"The story of being unexpectedly given a girl's underwear" "Iribitari ga ni manko tsukawasete morau hanashi" can
Analysis:
The inciting incident is purely pragmatic: the Gal, named Kyouko, needs a place to hang out after school, and the protagonist has an empty house. She effectively invades his space to play video games and relax. In exchange for his hospitality (and silence regarding her whereabouts), she offers him sexual favors. Iribitari Gal ni Manko Tsukawasete Morau Hanashi (roughly
Iribitari Gal ni Manko Tsukawasete Morau Hanashi (roughly translated as The Story of a Gal Who Stays Over and Lets Me Use Her
Please keep in mind that the original sentence may have a somewhat vulgar or humorous tone, depending on the context in which it's used. I've tried to preserve that tone in the translation while still making it readable and understandable in English. You can typically find it on adult manga
This title is primarily serialized as a dōjinshi or web manga. You can typically find it on adult manga hosting sites or specialty databases like Baka-Updates Manga MyAnimeList