It's interesting that their relationship to each other and to Kamishiro Maiku is dependent on whether it's the anime, manga, or light novel. Which one is Maiku's biological sister was shifted around between versions. In the LN Miina is Maiku's sister and Karen is unrelated to them. In the anime Karen is Maiku's sister and Miina is unrelated to them. In the manga Karen is Maiku's sister and Miina is their first cousin. Loosely the three versions are: Maiku chooses Karen, Maiku chooses Miina, and Maiku chooses family...
It's interesting that their relationship to each other and to Kamishiro Maiku is dependent on whether it's the anime, manga, or light novel. Which one is Maiku's biological sister was shifted around between versions. In the LN Miina is Maiku's sister and Karen is unrelated to them. In the anime Karen is Maiku's sister and Miina is unrelated to them. In the manga Karen is Maiku's sister and Miina is their first cousin. Loosely the three versions are: Maiku chooses Karen, Maiku chooses Miina, and Maiku chooses family...
Interesting. I only ever watched the show, I had no idea.