ストレートラインの作り方 - How to make a straight line.
http://www.tenkaradaio.sakura.ne.jp/tenkara/2020/fujino.htm
He writes that he believes more people are doing tenkara. Attracted by key words: easy, inexpensive, and no bait due to using kebari. And the attraction of being away from crowds in nature and on mountain streams.
But has noticed they are increasingly bringing Fujino’s “straight line” to introductory classes. Because while tenkara level line is excellent choice, the coil in the line must be taken out each time the line is deployed. The line coil if not removed causes casting problems for beginners, that is eliminated by using Fujino’s straight line.
Fujino straight line is ready made in 3 different lengths, item K-27: 3.3m, 3.6m, and 4.0m.
https://www.fujinoline.co.jp/archives/4458.html
However, since this spring Fujino Line has made available 2 different versions of their tenkara straight line in 10 meter spools. Allowing one to make a straight line of custom length to better balance rod length, line length, and stream size.
In his blog post he list the materials and shows the knots used to make his style of straight line of custom length. So that one might make their own line, to best fit countless situations.
Two types of 10 meter straight lines:
K-32 (green label) tenkara straight line, equivalent to 3.5号 line:
https://www.fujinoline.co.jp/archives/5941.html
K-33 (red label) tenkara straight line powerful , equivalent to 4.0号 line.
https://www.fujinoline.co.jp/archives/5936.html
Plus
K-24 tenkara easy mounting kit. A kit of 5 ready made chichiwa loops, to connect line to lillian.
https://www.fujinoline.co.jp/archives/3610.html
K-28 straight line marker kit. 3 pieces, 50cm in length, with black marks every 5 cm.
https://www.fujinoline.co.jp/archives/4498.html
Interesting that he notes that the marker lines are - " nylon 0.4×6 braids. Because it is a braided yarn, water penetrates and the tip becomes heavy" thereby becomes an aid to casting the line. Basically a weight forward shooting line.
Of course one can find many types of braided line to make custom made, non-coil memory tenkara lines, without ordering the Fujino Line products. Maybe Dr. Ishigaki’s method of knotting the lines might be of interest as a guide how to go about it.
The Fujino tenkara straight lines, K-32 and K-33 are both listed as having AQ Coat. That has as part of the symbol what looks like a drop of water. A few months back I did a little internet searching to see if I could figure out what AQ Coat [AQ コート, AQ kōto] is.
If I recall correctly, it was originally developed to be a floor wax or floor sealer to resist water penetration, abrasions, etc.
Fujino Lines web page about it - AQ コートとは？ - What is AQ Coat?
https://www.fujinoline.co.jp/aqcoat.html
A digital translation of the opening paragraph:
For traditional fishing line coating,
Fluorine processing and silicone resin are used,
AQ coat uses 100% plant-derived wax.
After coating the surface of the thread with wax, by heat setting with heat,
A strong film of wax covers the entire yarn, It protects well from water and scratches.
And from the AQ Coat website:
http://www.aqcoat.jp/
The floor coating has a tough protective film on the flooring to protect it from scratches, dirt, UV rays, and moisture, making it easy to carry out regular maintenance. About AQ coat. AQ coat uses “glass thin film” by nanocomposite technology.
[Sorry, but I could not provide links to digitally translated web pages. Every time I tried, I got the following error, with every translator I tried using :
400. That’s an error. Your client has issued a malformed or illegal request. That’s all we know. ] Hopefully the translation error is only a temporary problem, and it will work properly later.
Anyway, if you’d like to give Dr. Ishigaki’s method a try, but without using Fujino Line tenara straight line - I guess it’s pick your alternate line of choice, and maybe also your preferred floor wax and heat source. 
