Answer
There are only a few characters that are introduced by Haruki Murakami in the short story "The Seventh Man", including K, K's parent's, the seventh man's parents, the group of people in the house, K's dog, and of course, the seventh man himself, but out of all of these characters, only the seventh man is dynamic and round. The rest of the characters are all flat and static characters, and many aren't even mentioned more than a couple times. The seventh man is the storyteller that recounts his childhood and life story, which is most of what the story is about.
  The seventh man gave no name and is referred to as "the seventh man". For this reason, he is quite mysterious, because most people would provide their names, under the circumstances, but not the seventh man. He has been exposed to lots of grief, sadness, and bitterness at an early age, so he isn't, at all, a humorous man. After the tragedy, he didn't have a happy or deserved childhood. Instead, he was haunted by what he could have done and the tragedy kept coming back to haunt him. All the weight on his shoulders has made him heavy with sadness and serious. By his words, there isn't one trace of humor or lightness in his tone. The tragedy has also made him fear the ocean and any large body of water. He is constantly haunted by the fact that the water can drag him under just like it did to K, and he is constantly reminded of this from his recurring nightmares, which continued into his adulthood.
  It is often difficult to say or hear a loved one's name after they pass away. The seventh man misses his friend K extremely, and that is evident in the way that he never mentions his name and throughout the story, only calls him "K". Throughout his recount, his tone was somber with a trace of heavy sadness, even though he had previously forgiven himself. This also shows that he is someone who could hold grudges for a long time; possibly even for life. He held bitterness and a grudge against himself for not saving K when he could for over thirty years before he finally forgave himself. Even after he did, all the sadness over the years still rested in him for it takes much, much longer to take that away.
  I think the seventh man shared his story with a group of men he doesn't know because he wants them to understand that it doesn't help to turn away from something that causes fear and pain. He doesn't want what happened to him to happen to anyone else, because it stole from him the most important part of his life. It feels like everything he does, every major decision he makes--like moving away from town, never marrying, not getting close to the water--is to distance himself from the tragedy, but no matter how hard he tries, the memories still come back to him in the form of nightmares.
  The seventh man is, in a way, a dynamic character, because at the end of the story, he finally forgave himself and stopped blaming himself for the tragedy, but he still has that heaviness that is settled around him that he can't really shake off, which i believe will follow him for his lifetime.
