Why is the AAY still awake?

[Gurotsuki]

S/he haven't trim and polish the tail or back claws yet.

[The Horror Queen]

Reading far too much (impossible) horror manga followed up by the same genre of RPGs can keep a young weeaboo up throughout the night.

[patcher2girl]

She put off shopping until the last-last possible moment.

[Lied vom Tod]

She's up late because she feeds at night when people won't see her coming.

[Blank Dicer]

She is enjoying the beauty that nature has to show during night time.

[Jurgt]

They are practicing to improve their accuracy with compromised conditions. What better way to do that than to shoot at some empty cans at night while wearing a giant cat head? They also get to get back at their neighbor's frequent midnight drumming practice.

[Tsuki Amu]

It's far too cold to sleep, and besides, if they sleep, who would look at all that pretty snow?

[Payonai]

She has the night shift responsibility of guarding the royal palace. She enjoys napping during the day regularly, so she figured she would find a job that could work with her sleep schedule.

[Yuuna-Kiri]

He's originally a creature of the night. Of course he's still up. Especially since he needs the night to cool off an entire day of cooking in the sun. I mean, he's still smoking...literally. ;o

[StylishZombie]

She's sharpening her sword after an extremely late-night shift at a casino

[Esdella Vie]

He has restless leg syndrome... in all four legs. DX

[Barefoot Necromancer]

"The party's just getting started, she can't sleep now."

[MochiBlossoms]

"She ended up getting caught up in a book and simply lost track of time. She's never been one to sleep early anyways, though."

[User 33512697]

She's out meeting the very interesting people who populate the night, and expanding her worldview.

[Wabutan]

Simps: She appears to be a lady OF the night.