I'm not sure. It might have elements of reality, or it could be purely fictional. Without more context or specific knowledge about it, it's impossible to give a definite answer.
I've read a few Steve and Kono pregnant fanfictions. In one, the pregnancy was a surprise and it led to a whole new adventure for them. It showed how their relationship deepened as they prepared for parenthood. Another one was more about the challenges they faced, like Kono's health issues during the pregnancy and how Steve supported her through it all.
One emotional moment could be when Kono is injured during a mission and her friends fear for her life. They gather around her in the hospital, and the worry on their faces shows how much she means to them.
Koi was a very popular traditional cultural symbol, usually depicted as a fish with golden scales. In Chinese culture, koi represented good luck, wealth, and happiness. It was a symbol of many families and businesses. During festivals and celebrations, people would make koi ponds and release koi fish in hopes that they would bring good luck and happiness. Koi carp were also widely used in cooking and medicine. They were considered a kind of fish with magical effects.
Some writers develop Kono's character by making her reflective when she's hurt. She might think about her past actions, decisions she made that led to the situation she's in now. Maybe she regrets some things or realizes she needs to change certain aspects of how she approaches her work or relationships. This self - analysis is an important part of character development in the context of her being hurt in fanfictions.
We often call lucky people koi, but in fact, koi are not constellations but mythical creatures. According to legend, koi were creatures with good luck and longevity that could bring luck and blessings to people.
Astrology did not explicitly mention the connection between astrological signs and good luck. On the contrary, constellations were more used to study people's personality, characteristics, fate, and other factors.
Therefore, no constellation was a real Koi constellation. Good luck depended on one's efforts and actions, as well as the living environment and opportunities.
I'm not sure specifically as it could be a relatively unknown or niche visual novel. It might be about a unique story set in a particular world, perhaps with themes related to the end of this world ('kono yo no hate' can mean 'the end of this world' in Japanese), but without more information, it's hard to say for sure.