The Hunger Games movies clearly ripped off Battle Royale and BR2?

Isn't it obvious that The Hunger Games movies clearly ripped off Battle Royale and Battle Royale II: Requiem?

Hunger Games is no different to Battle Royale, all she has done is take the story of Battle Royale and then just go through it systematically changing every element, i.e the Japanese future to post apoplectic society, 40 Jap Kids to 24 kids for the districts, change in aesthetics, environment/world, from third person to first person, add in/take out characters, tweak characters, edit/make changes here and there, etc,etc. The main story is essentially the same, it uncanny and the underlying similarities with Battle Royale shows this method was used. You just don't get a story follow that closely to another story by chance. The tosh about it being similar to Gladiator, The Running Man, Greek mythology, etc is all just a smoke screen to distract from the real source Battle Royale. Its an often successful formula to follow, take a book that had a certain success level systematically create a version, edit out stuff that didnt work well, make it as relevant to today's society/age group that can relate and your book then stands a good chance of being at least successful if not more so, as if the original had a certain success level then your insuring yours will as well.