for your first tattoo i wouldnt condone koi fish on your side haha

1) You dont know how you will handle the pain
2) The ribs are a LOT of pain
3) Koi fish are 90% outline and they have to use a larger round (basically shading needles to get the thicker outline) since its so much outlining and that = more pain

so if you want to get it... i would move it to a different location.. here are my koi on my back