When I see this piece. All that goes through my head is, How is that possible? When I saw the thumbnail of this, I thought it was done digitally, when in actual fact, it's Traditional media! I adore the big contrast between the slightly coloured blacks and the bright, happy colours, it gives it a sort of evil-ish yet innocent charm. And I love the really warm and vibrant Red/Pink theme. This is so brilliant and intoxicating to me because any one who has tried something similar to this knows how extremely difficult it truly is e.g. Stop the pencil or paint bleeding or keeping everything precise & even. I can't really come up with a logical "suggestion to improve" because to me this is already perfect. Uhh, perhaps try a tiny bit of definition on the closest arm? But that kinda gives a fluid/light feeling to me. This is fantabulous.
By now I'm sure we've all seen a pretty girl in a kimono/yukata, but I must say her eyes are very striking to me. They have a depth, but it's soft and charming, almost pulling you in. The design isn't anything too original, but the pattern of her sash gives it almost a tribal feel, the added petals compliment the lace trim, and the bright red is a nice touch to offset the dark pattern.
Her right arm however bothers me. I can see where you were going with it, but the arch of it looks almost rubbery in a way, perhaps because her hand is angled strangely, and very thin. Under your pinky, it should be rounder to show the muscle underneath, but I see no definition of that here.
Overall, I love the pose and the bold colors you chose. Keep it up!