How can I make a good reverse harem manga?
Well, school-life reverse harems are the most common type, so if you really want to go for an original idea, you might want to choose a more creative setting… personally, I wouldn’t like a space station, but maybe keep the story in present-day but add supernatural/fantasy elements to it. Also, instead of just concentrating on the male characters, you should make sure that your main female character is someone who girls can relate to… preferably someone who doesn’t act in typically “girly” ways and breaks the mold a little bit, so that guys don’t fall for her right away (like Sunako in The Wallflower).