"Dreaming of Kimchee" Yashimoto Banana

This story is really enjoyable to read, looking into the protagonist's mind and feelings which reminds me how much she represents a person with depression. Throughout the story, the transformation she feels and goes through strikes me how similar it is to depression. When she was still having an affair, her life was very scripted with work and her leisure activities after work. She always ends up with a magazine that covers a topic of extramarital affairs, even though she always says it just happens to be that type of magazine every time and she only skims through it and not paying much attention in detail, it shows signs of a person in depression that is obsessive but at the same time in denial and always finding an excuse for themselves. Later on when she leaves her job and have time on her hands, that's when depression takes a bigger hit. When she was working, work occupied her but now that she has free time, the sense of loneliness and need for companionship and attention kicks in. While her husband is at work, loneliness overcame her until the very end when she reached a state of mindfulness.

Question: Shiomura always felt the carp is always looking at him, whether if it was during his time with Tsuyuko or in his home, is this simply his guilt? or does the carp represent something?