I dunno why ppl think she has no ass,seriously take a look at her sc4 concept art,you can see a small part of her buttcheeks from the front,wtf?oh and her ass is bigger than natsu's FYI,imagine Taki wearing what natsu is wearing oO............Yeah..
In SCIV Taki's in game model had a flatter ass than Natsu. Plus SCV's lighting makes Natsu's ass look huge. :D
In terms of art though they both have big asses. Natsu's buttcheek hangs out of her spandex suit and Taki's is just huge. xD
If Taki had an ass in the game like her art though. It would be the most distracting thing of all time. Also, I compared their XNALara models a few weeks ago out of boredom and Taki does have a bigger ass. The lighting just makes Natsu's look bigger. Natsu's model is also a little taller than Taki's. But Taki's ass is much bigger.
It isn't the hair, her chin is clearly higher than Taki's. Oh and I just did another comparison to verify my results. Taki's ass is only slightly bigger than Natsu's (in terms of ass profile). Taki's has a better shape though. Other thing about Taki's ass compared to Natsu's is Taki's just looks much more... slappable. xD