I made a holder and lid for the Takashima similar to the one for the Ikarashi. The Takashima is long, so long I had to turn the stone pond 90 degrees for it to fit.
The Takashima base and lid.:
Stone with top removed:
Both the Ikarashi and Takashima on the stone pond:
Gotta click to big 'em.
The oil stone sequence is a little quicker because there is no need to raise a slurry. The sequence is very similar. Start on the Atoma 1200, refine on either the Soft Ark or Washita, and finish on a Hard Black Ark with final polish on a Horse's Butt strop with green stuff.
Either set of stones works well and fast with Western O-1, Japanese White Paper #1 or #2. If you hollow grind PM-V11 either will also work well. Luckily I have no working A-2 iron in my shop (there are a few LN A-2 irons stored in the junk iron cabinet) so I do not know if either set of stones would work with A-2. I expect not.
Who knows where it will end because the synthetic Gukumyo could still be in the mix. For a synthetic water stone it is low maintenance and gives a very sharp, strong, edge. Damn I'm fickle.