BOYFRIEND DEFENSE ROUTE!Himegasaki Sakurako has become the platonic ideal of runner-up heroines. Unfortunately, her new boyfriend, Mimori Natsuki, is God's perfect dating sim protagonist, and the universe is sliding him into every route at once with every love interest archetype imaginable! Now Sakurako finds herself playing a completely different sort of game: boyfriend defense! Can she keep her beloved Natsuki from falling into the clutches of the many, many girls who can't stop falling for him?