Therefore, you need to devise interesting ways for their feelings to develop. If your game will have one, then find a way to make it logical.
Note that harems do not necessarily exist in doujin visual novels.
Perhaps you are interested in creating a cute story in which the main character can end up with one of several love interests.
Maybe you want to prove to the world that you can make a full-blown Dating Sim without problems like illogical choices (or gratuitous sex).
Or perhaps you want to mix some relationship elements into your mainstream video game. The first decision you make will unlock a major Event Flag for your story/game: If you're not creating a product with the intention of selling it, then know what you're getting into.
Do not talk about your awesome plans until your project is almost finished.However, there are examples of ren'ai games which take place in diverse genres, including but not limited to fantasy, science fiction, horror... These can often vary from good to bad to nihilistic.Don't let all of them be happy, because if the main character is not allowed to fail, then your story/game may lose its emotional impact.Just like in the Write a Magical Girlfriend Series entry, a male main character may be an Unlucky Everydude. Also, a main male character can sometimes be a Marty Stu who gets all the girls with no effort.Remember, you want your audience to sympathize with the main character, or perhaps imagine they could be him." Remember, it could get worse — if your story involves horror/dark themes, and if your main character is doing horrible things, then your audience may want to see themselves as anyone but that character.Note that Featureless Protagonist is exception to this.Maybe you can even go as far as to create a story in which the two people are more than just casual acquaintances at the beginning.If the game is a simulation, and the Official Couple continues their relationship, then your game could emphasize time management and making friends.This would be different from the many games in which the main character is unattached at the beginning, and the story is all about their finding love.However, as long as you're willing to write Multiple Endings, try to make sure all the pairings make sense.