You know, if the artists actually want to show that Hanamaru has a tummy, they don't even need to draw her all that chubby, they just have to change around the shading and show the slightest hint at body folds to portray what they want and it wouldn't do her cuteness any sacrifice.

Case and point, left is the original, right a slight edit I made.

//Edit: Decided to edit Kanan as well since if Hanamaru's tummy is "too big" for a swimsuit-shooting and Kanan is "too muscular" she deserves the same treatment. Again, just some changes in the shading and some very very slight changes to the arm to make the smallest muscle-curve