I get what you mean but there aren't many games like this, i can recommend
Star Periphery since it focuses more on relationships of the characters. There are 4 main girls the MC can interact with and many side girls that appear to different degrees, but the main focus is on the 4 girls, very good so far.
Another suggestion can be
CoC II and
TiTs, both very similar games. One is set in a Fantasy world and the other in space, in short the games are big with many characters. Some have extended interactions that can be counted as "relationships".
But i can also recommend erotic authors like
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who focus on slow burn stories.
Lastly, AI Chat can be an alternative as well, LLMs can roleplay crazy good by now. There is a reason why people fall in love with ChatGPT...