Go with your gut

Misora: Who do you want to choose?

Negi: Eh?

Misora: If those three, Nodoka, Ayaka and Makie, were here right now and you had to choose one, who would it be?

Negi: I can't...

Misora: Yes you can! Choose!

Negi: ...nodoka...i would choose Nodoka, but...

Misora: Problem solved. Choose Nodoka.

Negi: What about the others?

Misora: Negi-sensei, you really are blind. You worry so much about their feelings, you've forgotten the feelings of someone else.

Negi: Asuna? Konoka? S-setsuna? Ku-Fei and Kaede?

Misora: You! Relationships aren't just about making this girl happy or this girl sad. What about what YOU want? Who YOU want to be with? What, aren't you entitled to being happy too? Everytime one person is made happy, another is saddened. It's a cold, cruel fact of life, but its still a fact of life. If you want bookstore, you're gonna have to bite the bullet and break a heart or two (thinking: or twenty-five, by my last count [Zazie, Mana, Eva, Chao, Setsuna and whoever he picks are the exceptions, in case you were wondering]). If it helps, think of it this way: you'll be breaking their hearts, but you'll also be filling Nodoka's with happiness. And your own as well. If you don't choose, you'll break every last heart you're in, plus your's. This way, at least two of them can be happy. Better than none, right?