Takayama Pheasant Tail Kebari (wet fly, can fish dry until waterlogged)
*Thread 8/0 black or neon red if you want a hotspot.
*Hook - Moonlit ML062 barbless competition hook (curved shank, wide gape, similar to a scud hook), usually #12 for trout.
*Hackle - I like variegated such as Grizzly to emphasize movement. Webby if I want hackle movement and more sink, stiffer rooster if I want to use it for controlling the drift
*Body - Pheasant Tail
*Thorax - 3 peacock herl barbs spun into a dubbing loop is good but Hareline Ice Dub Olive Brown is more durable, easier to use, & has a UV flash quality in bright light.
*Rib - thin copper, optional. I don't normally use it, but can add durability, possibly faster sink.
Unlike most flies, the Takayama sakasa (reversed hackle) is usually tied from the head, hackle, then thorax and body, with the whip finish at the bend
The Sakasa Kebari, or reverse hackle fly, is probably the iconic "tenkara fly." I prefer partridge to pheasant for the hackle, and tie them a bit sparser.
www.tenkarabum.com
However, I often tie head, hackle, body thorax, and whip finish between the thorax and head, hiding the thread in the thorax dubbing.