If they barely interact with each other how is that they look like usch bros in this pic?
Because read the fucking last chapter.
I did it. But it came right out of fucking nowhere. I mean it was like the second time they even talk to each other? And now it turns out they're buddies. I'm not complaining about Signum and Nanoha bonding its just that i just sort of happened without any previous developing at all.
It's because we don't know about anything that goes on between end of A's and start of StrikerS other than Nanoha getting really hurt that one time.
Fate got too boring, so Nanoha decided to look for a more engaging lover.