1. This should be marked as erotica not suggestive, I was not expecting a full on sex scene in this let alone on page 1
2. The concept of marriage hunting does kind of exist in the English speaking world, it probably exists everywhere with a marriage culture, it just isn't always referred to as such. Professional matchmakers do exist and singles nights and speed dating are essentially the same thing as these parties, there is less emphasis on marriage during those events sure but the whole point is to find a partner and with any luck it would turn out well.
3. Everything you said about them not staying together is true but you also forgot that Aika isn't even really into women and seems to have just gone along with the flow and also lesbian marriages tend to have the highest rates of divorce in countries where gay marriage is legal