Freestone · Sedimentary · Shikoku

Yoshino River (upper / Ōboke)

Oboke and Yoshino-gawa river
Poor · Amago
Tenkara kebari (reverse-hackle) · 12–16
Poorlive now
Not the day for it
Low and clear — careful approach country. A morning for the obvious fish only.
90% confidence
What moved it
  • LevelLight rain recentlyNo gauge reading
  • Water temp22.5°C
  • ClarityClear
Today's fly
Tenkara kebari (reverse-hackle)
Tenkara kebari (reverse-hackle)12–16
A dependable searching pattern for these waters.
Conditions on the water
Estimate
Level
Light rain recently
No gauge reading
Water temp22.5°C
ClarityClear
Weather26°C
WindSW 3 km/h
Pressure1009 hPa
Rain · recent4.7 mm
Rain · ahead10.2 mm

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

Water temperature for Amago
Warm — slow
23°C est.ideal 9–17°C
0°14°28°
How to fish it · for Amago
When
Spring to the autumn closure
Where
The upper Yoshino carves the Ōboke and Koboke gorges through the spine of Shikoku, fast white water between steep schist walls, with amago and iwana in the…
Why this works
Water at 22.5°C. This is the line where catch-and-release kills masu salmon. Do not fish for them today.
Hatch timeline · todayPeak at 6pm

Hatch predictions

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Sub-surface · on the nymphunder the surface

Hatch predictions

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Beyond the hatch · worth watchingambient prey

Hatch predictions

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Evidence
ModelledModerate confidence

Modelled from regional ecology — no survey or occurrence data for this water yet.

Through the year
0–3 scale · August highlighted
J
F
M
A
M
J
J
A
S
O
N
D
Stenopsyche CaddisHatch
2
3
3
2
Cicada (Semi)Hatch
2
2
GrannomHatch
2
2
Evening SedgeHatch
2
3
3
3
2

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

Ranked for today
Amago 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
  • The main gorge is big water — fish the tributaries.
What's coming
Plan ahead
5-day outlook
Water here around 23°C. Nothing cooler within range — carry a thermometer.
Gallery · 2
  1. Oboke and Yoshino-gawa river
    Dramatic gorge with sheer rocky cliffs.
  2. Terrain map of the venue
    Terrain map
Conservation note

White-spotted char (iwana) and amago in the tributaries.

The full read · show the working · for Amago · confidence 90%
How the 10 is built — score × weight = contribution
Temperature5 × 28%1.4
Flow60 × 22%13.2
Clarity95 × 18%17.1
Feeding Time50 × 13%6.5
Pressure80 × 7%5.6
Insect activity56 × 12%6.7
Limiting factor: Water temperature (22.5°C) is outside Amago's preferred range (9–17°C)= 51
Can you trust it?
Water temperatureair-to-water estimateestimated
Level / flowon-river gaugeobserved
Prey activitymodelled from regional profilemodelled
What would change the calculation
Cooler water — back toward the 9–17 °C ideal band — would lift the score and ease welfare.
The dawn and dusk windows score higher than the midday lull.
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