This is my guess because I do not have experience with showas from Sakai, I only have sankes and one kohaku. From the looks of the pecs, I do expect sumi to tighten up. You could have a very nicely patterned showa when the sumi near the tail finishes.
One thing I noticed about kois from sakai-hiroshima is that there are different grades. Those with certificates are VERY good(so far)
, others are mixed bag.
