Freestone · Sedimentary · Shikoku, JP

Yoshino River (upper / Ōboke)

Oboke and Yoshino-gawa river
Tomorrow · Slow going — pick your moments
Sculpin Streamer
Forecast · Tomorrow
Slow going — pick your moments
Slow going — pick your moments and do not force it.
45% projected
Today's fly
Sculpin Streamer
Sculpin Streamer
Conditions on the water · Tomorrow
Estimate
Level
Heavy rain recently
No gauge reading
Water temp9.2°C
ClarityVery coloured
Weather13°C
WindN 25 km/h
Pressure1017 hPa
Rain · recent26.6 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
9°C est.ideal 7–14°C
0°14°28°
How to fish it · for White-spotted Char
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
Poor — water temperature is working for you, but water clarity is the limiting factor today.
Hatch timeline · tomorrowPeak at 6h

12h(now) — Autumn Olive

Stage: On emergersApproach: Emerger or dryActivity: 29%
Also:Autumn Needle Fly25%Black Midge23%
Peak emergence windowWeather boost10 food groups active

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

Beyond the hatch · worth watchingambient prey(1)

Hatch predictions

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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
Fly box · White-spotted Char
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
Other water nearby · 1
Niyodo River
56 km
30
White spotted char · Amago
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 White-spotted Char · confidence 45%
How the 30 is built — score × weight = contribution
Temperature100 × 28%28.0
Flow40 × 22%8.8
Clarity15 × 18%2.7
Feeding Time85 × 13%11.1
Pressure75 × 7%5.3
Insect activity63 × 12%7.6
Limiting factor: Water is very coloured — too coloured for White-spotted Char= 64
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