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.
Since I don't have detailed knowledge of this specific visual novel, it's difficult to say precisely. However, from the title, it seems that it has a connection to a son's friend. It might tell a story full of drama, with the relationship between different characters evolving as the story progresses. There could be emotional moments, conflicts, or revelations that are centered around the situation of being 'okasarete' (entrusted) to the son's friend.
The title suggests that the son and his friend are key characters. The son is a part of the equation as it's his friend involved. There may also be a parental figure who is doing the entrusting. Without more information, it's hard to say who else might be a main character, but it could be someone from the son or his friend's social circle who gets drawn into the situation.
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.
I'm not sure specifically which'madam koi koi real story' you are referring to. There could be many stories with that name or something similar. It might be a local story, a personal anecdote, or something unique to a particular community.
Visual novels often have unique art styles and narratives. Since we only have the title 'koi hi koi fu en visual novel', it's difficult to determine the exact content. It might tell a story set in a particular cultural context, given the use of Japanese - like words. Maybe it's about different relationships and the emotional nuances within them, but this is all speculation.
It's hard to say for sure. Ana could be a blend of real experiences and creative imagination. Maybe it takes inspiration from real-life situations but is not a complete account of actual events.
She could be an ordinary human who somehow gets caught up in the world of Greek mythology. For instance, she could be a student who is researching ancient Greek history and accidentally stumbles upon a portal to the demigod world. From there, she has to adapt quickly and becomes an important part of the story, perhaps even helping Percy in ways he didn't expect.