People · Japan
Kazumasa Tsutsui (筒井一雅)
Clock · top 5.9% of 32,817 all-time · competing since April 2025 · 2025TSUT01
Kazumasa Tsutsui (筒井一雅) has been competing for a year. His best event is the Clock: a personal-best single of 5.58, set at Japan Championship 2026, puts him in the top 5.9% of the 32,817 people who have ever been ranked in the event, and 22nd in Japan. Until December 2011, no official Clock solve in the world had been that fast. Across 13 competitions since April 2025, he has put 173 official solves on the record across six events. Solve to solve, his 3×3 times vary about 12% around a typical one, steadier than 73% of the 36,406 competitors with ten or more counted rounds. His 3×3 best has come down from 20.60 in April 2025 to 14.55, a 29% improvement. Kazumasa has entered 13 competitions, more competitions than 94% of everyone who has ever competed.
Standing, event by event
vs everyone ever ranked| Event | PB single | PB average | All-time standing | Japan | |
|---|---|---|---|---|---|
| Clock | 5.58 | 6.86 | top 5.9% | 22 / 268 | |
| Pyraminx | 4.65 | 7.05 | top 11.1% | 136 / 691 | |
| 3×3 | 14.55 | 18.97 | top 23.0% | 977 / 3,360 | |
| Skewb | 5.70 | 8.54 | top 23.5% | 128 / 354 | |
| 3×3 one-handed | 30.02 | 39.93 | top 46.8% | 361 / 539 | |
| Megaminx | 2:06.26 | 2:21.59 | top 49.4% | 234 / 313 |
Percentile against all competitors ever ranked in each event, a fairer measure than raw rank, because the pools differ by a factor of ten.
The line so far
Best single per competition, 3×3. Faster is higher — the axis is the right way up.
The story so far
- 21 Jul 2025First sub-15 3×3: 14.55 at Tokyo Summer 2025.
- 31 May 2025First sub-20 3×3: 18.30 at Kanto Spring 2025.
- 12 Apr 2025First competition: Tokai Spring 2025. A 20.60 3×3 single to start from.
Competitions
- Tokai Autumn 2026 · 11 Oct 2026 — 1 personal best set
- Japan Championship 2026 · 18 Jul 2026 — 1 personal best set
- Otsu Biwako Spring 2026 · 11 Apr 2026 — 1 personal best set
- Katano Spring 2026 · 21 Mar 2026
- Otsu Biwako Winter 2026 · 1 Feb 2026 — 1 personal best set
- Ota Winter 2026 · 25 Jan 2026 — 2 personal bests set
- Ota Autumn 2025 · 8 Nov 2025 — 1 personal best set
- Kansai Mega Day 2025 · 2 Nov 2025
- Katano Summer 2025 · 15 Sep 2025 — 1 personal best set
- Tokyo Summer 2025 · 21 Jul 2025 — 2 personal bests set
- Kansai Odd and BLD 2025 · 15 Jun 2025
- Kanto Spring 2025 · 31 May 2025 — 1 personal best set
- Tokai Spring 2025 · 12 Apr 2025
Reading this page: a single is one solve's time · an average is the middle three of five solves, best and worst discarded · a PB is a personal best · a DNF (did not finish) is an attempt with no valid result: a popped piece, an unsolved face, an over-limit memorisation · top X% compares against everyone ever ranked in that event, which is fairer than raw rank because event pools differ tenfold.
The circuit
The people whose scorecards keep turning up next to his.
- Haruki Tsutsui (筒井遥規) — met in 33 rounds, finished ahead once
- Hajime Miyazaki (宮崎朔) — met in 32 rounds, finished ahead twice
- Kantaro Sakamoto (坂本貫太郎) — met in 32 rounds, never finished ahead
Next targets
- A sub-5 Clock single — 1,444 people have one; it is 0.58 away.
- A sub-4 Pyraminx single — 10,050 people have one; it is 0.65 away.
Targets move as he improves.