This is a classic for sure. Although I'm not much for relationships where the main leads argue all the time, this story is gold to me. Domyouji, the main lead, is violent, spoiled, and impulsive but his love for Makino, the mc, is so great that it draws you in. He shows his love again and again all throughout the series and as you read you can see how he changes to be a better person just for her. He is for sure one of my favorite characters ever and he indisputably is the main ingredient for what makes this manga's popularity immortal.
Hana Yori Dango