I'm not sure without reading the book, but it could be soldiers on the front line, their families waiting at home, or the people involved in the war effort like nurses or commanders.
Since it's a novel about letters from war, there may be a central character who is a soldier. This soldier could be from a particular region or background. His personality might be shaped by the war. Alongside him, there could be other characters like his childhood friend who also joined the war, or a local civilian in the war - torn area that he interacts with. And of course, the people he writes to, such as his father who might be a veteran of a previous war and has his own views on the current conflict, and his sweetheart who is waiting anxiously for his return.
Chapter 788, "Don’t be so fierce, I'm scared", is the clearest early answer because it turns Lu Yafei's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Song Xue covered her mouth in shock. and follows through with I hope it can help me atone..
Chapter 664, "Record a Major Mistake", is the clearest early answer because it turns Xi Yang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Shiguang and Xi Yang are fighting?
Chapter 549, "Is This How You Be a Brother?", is the clearest early answer because it turns Brother's situation into a concrete plot event. The chapter gives readers a real answer by opening on Jiang Li led her group deeper into the island.
Chapter 754, "Evil Can Never Defeat Justice", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from After the court trial ended, everyone immediately threw a party for...
Chapter 646, "This person deserves a slap in the face!", is the clearest early answer because it turns Don's situation into a concrete plot event.
Chapter 848, "Just an Adopted Daughter", is the clearest early answer because it turns Gu Qiang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with With a "snap," the old lady slammed the photo onto the table, clearly...
Chapter 547, "What a bustling family you all are", is the clearest early answer because it turns Mr's situation into a concrete plot event. It opens with Because of the unsightly scandal caused by watching the live...
Chapter 864, "What if he just wants to take revenge on you?", is the clearest early answer because it turns Red Bird Evil's situation into a concrete plot event.
Chapter 762, "Your Son is Even Worse than a Mountain Pig!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on The suit was immaculate, and he was very dashing.
Chapter 626, "Emergency PR!", is the clearest early answer because it turns Zheng Xun's situation into a concrete plot event. The chapter gives readers a real answer by opening on The drone hovering in mid-air had precisely captured this scene, and...