Koi (鯉) is carp, and Japanese carp fishing looks nothing like the European version. No reel, no bite alarm, no lead thrown eighty metres. Instead there is a telescopic pole of four or five metres, line of about four pounds tied to the tip, and a fish that will comfortably outweigh the breaking strain several times over. The whole method rests on the blank absorbing what a drag would otherwise handle.
The angler fishes from the bank at a chosen spot, with a pole matched to the water in front of them. Line runs roughly to the length of the rod and is tied straight to the tip, so everything the fish does is answered by the rod and by the angler's footwork.
Bait is placed rather than cast, and the fishing is patient. Carp are approached where they feed, on rivers, canals and stillwaters, and a session can be a long wait followed by a very fast few minutes. When a fish takes, the only line to give is what the pole itself yields, so the angler works the fish by angle and by the bend in the blank, walking it away from snags rather than pulling against it.
The fine line is not bravado. Carp inspect a bait closely and refuse thick line, so the whole rig is built down to what the fish will accept and the rod is built up to compensate. A 0.8号 leader on a 5.4 m pole is a balanced outfit in this discipline, and it would be an eccentric one anywhere else.
Competition fishing runs through the sport and is marked in the catalogue: Nissin's 競技 (kyogi) models are built for it, where landing speed on fixed tackle is what separates anglers.
Reading the numbers
A hardness grade, and line finer than you would believe
Hardness 2.5H to 8.5H, written number-first. Higher is stiffer
⚠ Not the ayu H scale, despite the shared letter. The two do not convert
Line 号 is a diameter: 0.6-3号 nylon, usually 0.8-1.5号, roughly 3-6 lb
No lure, casting or power rating exists. There is no reel and nothing is cast
The blank is the only drag, which is what makes such fine line workable
How koi rods are rated
Hardness across the 26 rods in this discipline that publish one.
Hardness (H)
26 rods with a hardness grade · busiest at 4-4.75H
⚠ Koi runs 2.5H-8.5H. This is not the ayu H scale, which runs H2.25-H4.0 and writes the letter first.
Where it comes from
Carp have been fished in Japan for centuries and the tackle stayed on the fixed-line path that hera, tegek and the other pole disciplines share, while Europe went the other way entirely. That divergence is the most useful thing to understand about these rods.
A European carp rod is a casting tool: twelve or thirteen feet, a test curve in pounds, a large reel, and a lead thrown a long way to a baited spot. It is built to reach fish and then to subdue them with drag. A Japanese koi rod is a pole: four to eight metres, no reel, a hardness grade instead of a test curve, and line measured in 号. It is built to present a bait close in and then to cushion a fish that has nowhere to be played from. Both are in this catalogue and they are separate disciplines, filed as carp and koi, because almost nothing transfers between them.
The length ladder follows the Japanese convention exactly, stepping in 0.9 m increments through 3.6 m, 4.5 m, 5.4 m, 6.3 m, 7.2 m and 8.1 m, which are three-shaku steps in metric dress. The busiest rungs are 4.5 m and 3.6 m. It is the same ladder the tegek poles use, a reminder that these disciplines grew from a shared idea of how a pole should be sized.
Two qualifiers recur in the series names. 小継 (kotsugi) marks a short-jointed build that collapses into a notably shorter package for transport, and 競技 (kyogi) marks a competition model. Both brands here name every relevant series for the fish outright, so there is no guesswork about what these rods are for.
Choosing a koi rod
Match the length to the swim, on a 0.9 m ladder. The range steps 3.6, 4.5, 5.4, 6.3, 7.2 and 8.1 m, and 4.5 m and 3.6 m carry most of it. Length is reach and it is also cushioning, so a longer pole protects fine line better at the cost of weight in the hand.
Read the hardness grade as your trade-off. Lower grades bend deeper and forgive more, which is what keeps a 0.8号 leader intact. Higher grades give control and turn a fish faster, which matters near snags and in a match. With no power rating to fall back on, this is the decision.
Do not carry an ayu grade across. Both use an H scale and the numbers do not mean the same thing. The ranges barely overlap and the notation is reversed, so treat them as unrelated.
Take the weight seriously. These run from around 60 g up past 300 g, and you hold the rod unsupported with no reel seat to rest against. Over a long session that figure matters more than it looks like it should.
Consider a kotsugi build if transport matters. 小継 models collapse into a shorter package than a standard telescopic of the same length, which is worth having if the walk to the water is long or the rod travels by train.
The koi cohort at a glance
Length, rod weight and maker across every rod declared for this fishery.
Length
89 rods with a length
Rod weight
89 rods with a published weight
Makers
Gamakatsu53
Nissin36
Featured koi rods
One rod from each maker that builds for this fishery, drawn from the ideal envelope above.