Sometimes, they get injured accidentally, like in a potions accident gone wrong in the Hogwarts dungeons. This then leads to a series of events where they learn more about each other's vulnerabilities and strengths. It can also bring out the protective sides of their friends, like Harry trying everything he can to make sure they are okay.
A common plotline is Hermione getting injured during a battle or a dangerous adventure. For example, in many fanfics, she might be hurt while exploring an old, dark wizard's lair. Another is getting injured by a magical experiment gone wrong, like in some stories where she's trying a new, untested spell.
One common plotline could be Hermione forming a closer friendship with Fleur. Since she hates Ron, she might turn to Fleur for support and they could end up having adventures together, perhaps in the wizarding world outside of Hogwarts.
There's often the sacrifice plotline. They might sacrifice their relationship with Hermione to save a large number of people. For instance, they learn that a dark wizard will spare many lives if they abandon Hermione. Also, the jealousy plotline can exist. If a new character becomes closer to Hermione and they feel left out, they might leave out of jealousy and a sense of not belonging in Hermione's new social circle.
A common plotline is where they decide to explore the Muggle world together. Ron is always curious about Hermione's Muggle - born background. They get into all sorts of comical situations as Ron tries to understand things like cars and telephones. And of course, their love for each other grows even deeper during this exploration as they see new sides of each other that they hadn't before.
A very interesting plotline is when their children have to face a new dark force in the wizarding world. This forces them to rely on the skills and values taught by Ron and Hermione. The story might also include how they use their parents' old friends and resources to combat this threat, while also growing as individuals in their own right.
A plotline where they form a secret club at Hogwarts. They have to keep it a secret from the teachers and other students while they work on a special project. It could be something like creating a new spell or trying to communicate with a magical creature that has never been done before. Their different personalities would lead to both funny and tense situations within the club.
One interesting plotline could be that after a long time apart, Ron and Hermione reunite during a dangerous mission. They realize that their feelings for each other are still as strong as ever, and they have to work together to overcome the challenges in the mission while also rekindling their relationship. Another plotline might be that they reunite at a Hogwarts reunion. There, they see how much they've both changed yet how their connection remains deep. They then start to share all the things that have happened to them in the years since they last saw each other.
One common plotline is that Legolas gets injured while protecting his friends. For example, he might jump in front of a weapon aimed at Aragorn or Gimli. His injury then becomes a test of the group's loyalty and friendship as they strive to heal him.
One common plotline is Inuyasha getting injured during a battle with a powerful demon. Then, his friends, especially Kagome, have to take care of him and protect him while he recovers. This often leads to some tender moments between the characters.
One common plotline is his friends or allies coming to his aid. For example, in some fanfictions, Aang might use his healing abilities to help Zuko. This can lead to a deeper bond between them.