Yumiki — Kyudo Log

Counting how many arrows hit today will not show you the path to improvement.
Yumiki records where each arrow lands, and reveals your progress as the scatter of your arrows tightens — a practice log built for kyudo, Japanese archery.

■ Arrow by arrow, round by round
Record hits by tachi (round). A hit is a navy outlined circle; a miss is a crimson × — encoded by shape and colour together, so it reads correctly in black-and-white print and for colour-blind archers alike.
To record where an arrow landed, just tap the kasumi target. Four-arrow or two-arrow rounds, either way.

■ Grouping tells the real story
Hit rate is only the outcome. Yumiki derives what actually drives it:
• Spread σ, in centimetres — how large your group is
• Centre shift — whether your aim drifts high, low, left or right
• Confidence ellipse — the shape and tilt of the group
As σ shrinks and the centre moves in, the hit rate follows. You can watch improvement in the order it really happens.

■ See the whole practice
• Hit-rate and arrow-count trends
• Arrow scatter plot, with σ and centre-shift trends
• Practice frequency by weekday
• Personal best
• Calendar view, colour-coded by hit rate

■ PDF report
Export your practice to an A4 PDF — scatter plot, charts, equipment and grading history on one sheet. Show it to your teacher, or print it to mark a milestone.

■ Review your form from a photo
Estimate joint angles from a photo and tag it with the stage of hassetsu. Analysis runs entirely on your device — no photo is ever uploaded.

■ Everything around the practice
• Bows, arrows, strings and gloves, linked to each session
• Grading (dan) and examination history
• Weather, wind, condition, focus — and your own reflections
• Export and import your data

■ Privacy
No account. No network requests.
Your records, photos and analyses stay on your device. We cannot see your data, because it never reaches us.

■ Languages
日本語 / English / 简体中文
Large-text mode available in settings.

Seisha hitchū — a correct shot hits. It begins with recording correctly.