Hmm I've decided Haruka and Akane AT THE SAME TIME
They're sisters they shouldn't mind sharing
PS I don't think any of them are too "young" for me, I'm only 19 going on 20.
So if I take the rule of dating age...20/2 + 7 = 17 which is the youngest girl I can date.
Haruka is 20-21, so that's not too bad either
Ayu and MyuMyu might be too young however.