Freestone · Limestone Influenced · Shikoku, JP

Niyodo River

Niyodo River in Ino town, Kochi pref Japan

The Niyodo is famous for a colour — 'Niyodo blue', the luminous clarity that limestone gives its water — and runs through the green mountains of Kōchi as one of the most beautiful rivers in Japan, holding amago and iwana in pools you can see straight to the bottom of.

Tomorrow · A proper day on the water
Sculpin Streamer
Forecast · Tomorrow
A proper day on the water
A proper day for it. Work the seams with an upstream nymph, switch to the dry when they show.
90% projected
Today's fly
Sculpin Streamer
Sculpin Streamer
Conditions on the water · Tomorrow
Estimate
Level
Moderate rain recently
No gauge reading
Water temp10.5°C
ClarityClear
Weather16°C
WindN 20 km/h
Pressure1015 hPa
Rain · recent22.0 mm
Rain · ahead0.0 mm

No gauge on this water — readings are regional estimates from weather, not a live gauge.

Water temperature for White-spotted Char
Ideal
11°C est.ideal 7–14°C
0°14°28°
How to fish it · for White-spotted Char
When
March/April to the autumn closure
Where
The Niyodo is famous for a colour — 'Niyodo blue', the luminous clarity that limestone gives its water — and runs through the green mountains of Kōchi as one…
Why this works
Poor — water temperature is working for you, but water clarity is the limiting factor today.
Hatch timeline · tomorrowPeak at 6am

12pm(now) — Autumn Olive

Stage: On emergersApproach: Emerger or dryActivity: 52%
Also:Black Gnat49%Autumn Needle Fly44%
Peak emergence windowWeather boost10 food groups active

Peak activity at 6am — Kajika Sculpin (Japan) (Kajika Sculpin (Japan), Weather boost)

Sub-surface · on the nymphunder the surface

Hatch predictions

Top nymph shown — see all 3 guilds as a supporter.

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Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

Supporters see what else is on the menu.

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Evidence
Records-basedModerate confidence

Based on species-occurrence records, not local invertebrate surveys.

Through the year
0–3 scale · October highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
Ephemera strigata (Mid-Reach Keiryu Mayfly)Hatch
2
3
3
3
2
Epeorus latifolium (Riffle Mayfly)Hatch
2
3
3
3
3
3
2

Numbers are intensity 0 (none) to 3 (peak) — a guide, not a guarantee.

Ranked for today
White-spotted Char fly box
EH
Elk Hair / Stenopsyche caddis
12–14 · Sedge
Evening sedge — twitch or dead-drift it as the light goes.
CB
Cicada & beetle terrestrials (midsummer)
10–12 · Terrestrial
Fish it tight to the bank on warm, breezy days.
Permits & access
Permit required — see local rules.
  • Co-operative yugyoken required; spawning closure in autumn
  • Confirm reach and method rules.
What's coming
Plan ahead
5-day outlook
Fishing better nearby · 2
Shimanto River
50 km
80
White spotted char · Amago
Yoshino River (upper / Ōboke)
56 km
30
White spotted char · Amago
Gallery · 2
  1. Niyodo River in Ino town, Kochi pref Japan
    Clear water river in Shikoku.
  2. Terrain map of the venue
    Terrain map
About this water

The Niyodo is famous for a colour — 'Niyodo blue', the luminous clarity that limestone gives its water — and runs through the green mountains of Kōchi as one of the most beautiful rivers in Japan, holding amago and iwana in pools you can see straight to the bottom of. Sight-fishing water in a landscape of gorges and clear pools.

Under the surface

A river celebrated for its luminous limestone-blue clarity, running through the green Kōchi mountains of Shikoku. Amago and iwana hold in pools so clear they seem bottomless; this is sight-fishing water, gorge and pool and astonishing colour.

Wading: Gin clear water, slick bedrock — stealth essential

  • River
  • Limestone influenced
  • Confined
  • Pool riffle
  • Pocket water
Conservation note

White-spotted char (iwana) and amago — the prized Shikoku red-spotted native.

The full read · show the working · for White-spotted Char · confidence 45%
How the 30 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow60 × 22%13.2
Clarity15 × 18%2.7
Feeding Time70 × 13%9.1
Pressure75 × 7%5.3
Insect activity64 × 12%7.7
Limiting factor: Water is very coloured — too coloured for White-spotted Char= 66
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
A drop and clear would lift the flow and clarity scores.
Directions
Apple MapsGoogle Maps
Seasons & zones
  • Char late February to April → late September to mid-October

    Honshu/Shikoku/Kyushu keiryu are managed by local fishery co-operatives — a yugyoken (day/annual ticket) is required, and most streams close around 30 September / mid-October for spawning. Species are surfaced in prose only (no engine slugs for yamame, amago or iwana). Legal status: guidance_not_permission.

Related guides
Euro Nymphingsubsurface methods
Booking & contacts