Yeah, all the girls are included.
I'm using the popular OCEAN personality system (openness, conscientiousness, extroversion, agreeableness, neuroticism) and I added an S - sexuality. So... six categories—OCEANS. Each girl gets a 1-6 ranking in the system, 6 being their highest trait. When you finish the questionnaire, your top 3 traits are checked against every other girl's top 3 traits. Whoever you match with is the winner.
I tried like five different systems to generate a reasonable amount of work... the truth is, it's a nightmare to make completely fair due to the possibility of ties. Most systems use the 1-5, strongly agree to strongly disagree setup to solve this issue, but I hate how boring and impersonal that is.
So, with three answers for each question, I wrote a question for every combination of three traits. OCE, OCA, OCN, etc. That means 20 questions to account for every possibility. This method eliminates favoritism for any specific trait, although the "quirkiness" of the answers definitely skews the results. Still, there can be ties, but what does it mean if there actually is a tie, you know? If someone is equal parts open and agreeable, there's no need to adjust it. Instead, only if there are ties, I randomize the tied attributes and assign a girl.
It's imperfect, but getting a girl with OES instead of OSE is reasonable considering that, in reality, the guy taking the test would be happy with either girl (because he's equal parts EOS), and also because this is an erotic visual novel and working out every possibility would be a ridiculous waste of time.
...I'm dumb.