The “Innocent Gr...” (presumably “Innocent Grandma” or “Innocent Groom”) finds themselves at the mercy of a matriarch who abandons traditional warmth for sharp-tongued dominance. The plot, as pieced together from user comments and clips, follows a young couple’s struggle to maintain their lifestyle under the roof of a rude, manipulative grandmother who seems intent on destroying their peace—and perhaps their relationship.
In this first installment, the "lifestyle" aspect refers to the simulation of a shared living environment. The game tracks daily routines, chores, and the mounting tension of living with someone who is intentionally abrasive.
NTR Part 1 - Rude Grandma" appears to be a specific niche creative work—likely an adult-oriented manga or light novel, given the "NTR" (Netorare) tag and the "Innocent Grandson" title—rather than a mainstream lifestyle film or book.