Japan Chess Championship 2026 -The 27th Argentina Cup-

SwissStandard

67 players participated in this 9-round tournament, held from 02 May 2026 to 06 May 2026 in Tokyo, Japan. 13 titled players. Top 10 Elo average was 2224, and top seed was Thanh Tu Tran (🇯🇵 JPN, IM, 2402).

Kan Nakahara (🇯🇵 JPN, CM, 2244) won with 7.5/9, ahead of Thanh Tu Tran (7.0) and Shinya Kojima (6.5). Nakahara shared the lead from round 7 and won solo starting round 8.

The biggest upset came in round 2: Keito Sato (1664) beat Chiaki Fujii (2043), a +379-point gap.

Location

🇯🇵Tokyo, Japan

Dates

02 May 2026 → 06 May 2026

Time control

Standard: 90 minutes with 30 second increment from move 1

System

Swiss · 9 rounds

Top seed

🇯🇵IMThanh Tu Tran2402

Avg top 10

2,224

Participants

Titled players · 13

IM×3

FM×3

CM×4

WCM×3

Federations · 1 represented

🇯🇵Japan×67

Top 3

🥇
CMKan Nakahara
🇯🇵JPN·2244
7.5pts·2446perf+45.8
🥈
IMThanh Tu Tran
🇯🇵JPN·2402
7.0pts·2340perf-3.4
🥉
IMShinya Kojima
🇯🇵JPN·2307
6.5pts·2307perf+2.2

How it unfolded

Top 6 · 9 rounds

CM Kan Nakahara led from R4; +0.5-point edge over the runner-up.

Co-leaders

Nakahara7.5Tran7Kojima6.5Otsuka6.5Dryglas6.5Yamada6.5— ex-leaders:Nanjoled R6, #7

R6 · LEADER CHANGE04 May

IM Ryosuke Nanjo takes the sole lead (5.5/6).

R9 · HEAD-TO-HEAD · WINNER VS 2ND

CM Kan Nakahara drew with IM Thanh Tu Tran (White).

WIN STREAKS · 3 top finishers

CM Kan Nakahara 5 wins (R1–R5)IM Thanh Tu Tran 3 wins (R3–R5)IM Shinya Kojima 3+3 wins (R1–R3, R5–R7)

Key matchups · top 4

Head-to-head between the four finishers

Player	1	2	3	4
1CMKan Nakahara	*	½	1	1
2IMThanh Tu Tran	½	*	1	0
3IMShinya Kojima	0	0	*	—
4FMShou Otsuka	0	1	—	*

Grille américaine

#	Player	Elo	Fed	R1	R2	R3	R4	R5	R6	R7	R8	R9	Pts	Bu C1	Bu	SB	Perf	Δ
1	Nakahara, KanCM	2244	JPN	+34B	+30N	+15B	+3B	+5N	−7N	+4B	+8B	=2B	7.5	48.5	53.0	43.50	2446	+45.8
2	Tran, Thanh TuIM	2402	JPN	+20B	=12N	+48B	+13N	+21B	−4N	+14B	+3B	=1N	7.0	47.5	51.0	38.00	2340	-3.4
3	Kojima, ShinyaIM	2307	JPN	+36B	+9N	+14B	−1N	+30B	+6N	+7B	−2N	=5B	6.5	49.5	54.0	36.25	2307	+2.2
4	Otsuka, ShouFM	2322	JPN	+32N	+31B	−8N	+28B	+15N	+2B	−1N	=9B	+12N	6.5	46.5	51.0	34.50	2259	-7.8
5	Yamada, KoheiFM	2182	JPN	+25N	+26B	=6N	+22B	−1B	+21N	=41B	+7N	=3N	6.5	46.5	50.5	34.50	2193	+7.0
6	Dryglas, Maciej	2082	JPN	+38B	+43N	=5B	−21N	+37B	−3B	+39N	+28N	+13B	6.5	40.0	44.0	29.25	2148	+17.4
7	Nanjo, RyosukeIM	2301	JPN	+42N	+28B	=29N	+8B	+12N	+1B	−3N	−5B	=9N	6.0	47.0	51.0	32.75	2227	-6.5
8	Kobayashi, AtsuhikoCM	2130	JPN	+46B	+53N	+4B	−7N	+9B	=41N	+10B	−1N	=15B	6.0	45.5	49.0	30.75	2210	+20.6
9	Matsuo, TomohikoCM	2032	JPN	+60N	−3B	+32N	+17B	−8N	+16B	+22N	=4N	=7B	6.0	45.5	48.0	29.25	2157	+24.8
10	Higashino, Tetsuo	2117	JPN	=21B	=23N	=37B	=38N	+32B	+24N	−8N	+40B	+41B	6.0	37.5	41.5	26.50	1997	-23.0
11	Fujii, Chiaki	2043	JPN	+47B	−48N	−41B	−23N	+52B	+56N	+25B	+17B	+22N	6.0	35.5	38.5	26.00	1875	-30.2
12	Nagataki, Kota	2037	JPN	+33N	=2B	+49N	+29B	−7B	−14N	+21B	+41N	−4B	5.5	43.0	46.5	25.00	2148	+25.4
13	Shioguchi, Tatsuya	2034	JPN	=23B	+61N	+24B	−2B	=22N	+38N	=28B	+14N	−6N	5.5	42.5	45.0	24.25	2068	+7.4
14	Averbukh, AlexCM	2126	JPN	+40N	+39B	−3N	=35B	+49N	+12B	−2N	−13B	+24B	5.5	42.0	45.5	24.25	2112	-1.8
15	Yonemitsu, Kohei	2080	JPN	+67N	+37B	−1N	+39B	−4B	+25N	F	+16B	=8N	5.5	40.0	40.0	23.00	2151	+15.8
16	Higashishiba, Teruomi	1925	JPN	=22B	+57N	−21B	+36N	+50B	−9N	+30B	−15N	+53B	5.5	37.5	40.5	21.50	1977	+10.6
17	Tanaka, Satoshi	1900	JPN	+44B	−29N	+62B	−9N	+55B	=53N	+35B	−11N	+28B	5.5	36.0	38.0	19.75	1955	+7.8
18	Matsunaga, Toma	1930	JPN	=51N	+55B	−22N	=40B	=19N	=49B	+43N	=29B	+30B	5.5	34.5	37.5	22.00	1978	+21.6
19	Yamamichi, Atsuya	1816	JPN	−29B	−62N	+52B	+58N	=18B	=32N	+27B	=53N	+35B	5.5	34.0	36.0	22.75	2019	+76.4
20	Kuroda, Yunosuke	1874	JPN	−2N	−60B	−66N	=33B	+63N	+54B	+42N	+39B	+29N	5.5	32.0	33.5	20.25	1995	+27.2
21	Togawa, Kentaro	1826	JPN	=10N	+45B	+16N	+6B	−2N	−5B	−12N	+49B	=31N	5.0	45.5	49.0	24.75	2061	+89.2
22	Mizohata, Kyotaro	0	JPN	=16N	+63B	+18B	−5N	=13B	+37N	−9B	+26N	−11B	5.0	44.0	46.0	22.00	1993	0.0
23	Noda, Ryo	1756	JPN	=13N	=10B	−39N	+11B	+26N	−28B	=49N	=37B	+43N	5.0	39.0	42.5	24.50	2014	+115.6
24	Kihara, Taira	1887	JPN	=45N	+50B	−13N	=55B	+48N	−10B	+51N	+31B	−14N	5.0	36.0	39.0	18.50	1925	+13.6
25	Sakai, AzumiWCM	1843	JPN	−5B	+59N	−53B	+62N	+31N	−15B	−11N	+58B	+37N	5.0	36.0	38.0	16.50	1927	+13.2
26	Okabe, Yuma	1951	JPN	+59B	−5N	−38B	+47N	−23B	+55N	+50B	−22B	+40N	5.0	35.0	38.0	17.50	1836	-17.8
27	Kitagami, Show	1890	JPN	−55N	=33B	=51N	+45B	−40N	+48B	−19N	+57B	+42N	5.0	32.0	35.0	18.50	1799	-15.4
28	Noguchi, Koji	1981	JPN	+52B	−7N	+46B	−4N	+34B	+23N	=13N	−6B	−17N	4.5	43.5	47.0	19.75	1977	-2.8
29	Moritani, Sho	2105	JPN	+19N	+17B	=7B	−12N	−41B	=50N	+34B	=18N	−20B	4.5	42.0	45.5	23.00	1945	-63.6
30	Taga, Hiroto	1991	JPN	+66N	−1B	+42N	+48B	−3N	=39B	−16N	+33B	−18N	4.5	41.0	42.5	15.50	1929	-14.6
31	Furuya, Masahiro	2012	JPN	+56B	−4N	+34B	−41N	−25B	+44N	+38B	−24N	=21B	4.5	38.0	41.0	18.00	1848	-35.8
32	Yanai, Yuya	1871	JPN	−4B	+56N	−9B	+59N	−10N	=19B	−33N	+63B	+57N	4.5	37.5	39.5	13.75	1879	-1.0
33	Aoki, Yasuhiro	1764	JPN	−12B	=27N	−44B	=20N	+65B	=46N	+32B	−30N	+49B	4.5	36.5	38.5	17.25	1920	+33.6
34	Araki, Dai	1843	JPN	−1N	+64B	−31N	+60B	−28N	+45B	−29N	=52B	+51N	4.5	34.5	36.5	13.75	1843	-3.6
35	Gishi, Takeshi	1945	JPN	−48N	+67B	+60N	=14N	=38B	=40B	−17N	+51B	−19N	4.5	34.0	35.5	14.25	1809	-30.6
36	Saito, Hiromasa	1870	JPN	−3N	+66B	=54N	−16B	−51N	+58B	−57B	+44N	+50B	4.5	32.5	34.0	13.75	1691	-29.4
37	Sakai, Enju	1880	JPN	+58B	−15N	=10N	+54B	−6N	−22B	+46B	=23N	−25B	4.0	40.5	43.5	16.00	1918	+5.6
38	Niori, Toma	1804	JPN	−6N	+58B	+26N	=10B	=35N	−13B	−31N	=50N	=39B	4.0	39.5	42.5	17.00	1909	+32.8
39	Yamaguchi, Tosei	1939	JPN	+65B	−14N	+23B	−15N	+56B	=30N	−6B	−20N	=38N	4.0	39.5	41.5	14.25	1852	-19.2
40	Patil, Rushad	1831	JPN	−14B	=44N	+57B	=18N	+27B	=35N	=53B	−10N	−26B	4.0	39.0	42.0	16.75	1913	+15.2
41	Hashimoto, Shunji	1859	JPN	F	F	+11N	+31B	+29N	=8B	=5N	−12B	−10N	4.0	39.0	39.0	21.25	2139	+100.0
42	Tanaka, Ryosuke	1850	JPN	−7B	+52N	−30B	−56N	+59B	+62N	−20B	+47N	−27B	4.0	34.5	36.5	12.50	1775	-19.8
43	Shakuya, Keita	1887	JPN	+62B	−6B	=55N	−50N	=44B	+47N	−18B	+56N	−23B	4.0	34.5	36.5	12.50	1783	-14.8
44	Terasawa, Koshiro	0	JPN	−17N	=40B	+33N	−49B	=43N	−31B	+60N	−36B	+59N	4.0	33.5	36.0	14.00	1800	0.0
45	Sakamoto, Akihiro	0	JPN	=24B	−21N	+61B	−27N	=46B	−34N	−52B	+67N	+56B	4.0	32.5	34.0	11.50	1766	0.0
46	Abe, Taro	1842	JPN	−8N	+65B	−28N	=66B	=45N	=33B	−37N	=54B	+52N	4.0	32.0	33.5	12.25	1814	-7.8
47	Uetani, Toshiaki	1765	JPN	−11N	−54B	+64N	−26B	+66N	−43B	+48N	−42B	+55N	4.0	31.0	32.5	10.00	1773	-1.4
48	Sato, Keito	1664	JPN	+35B	+11B	−2N	−30N	−24B	−27N	−47B	+60B	=54N	3.5	39.5	42.0	14.75	1851	+70.4
49	Honda, Yoshiki	1908	JPN	=50N	+51B	−12B	+44N	−14B	=18N	=23B	−21N	−33N	3.5	38.5	42.0	14.50	1704	-37.6
50	Baze, Rejold	0	JPN	=49B	−24N	+63N	+43B	−16N	=29B	−26N	=38B	−36N	3.5	36.0	38.0	12.00	1822	0.0
51	Matsumoto, Yuya	1597	JPN	=18B	−49N	=27B	=61N	+36B	+57N	−24B	−35N	−34B	3.5	35.5	38.0	14.00	1780	+73.2
52	Ivanov, Elizabeth	1710	JPN	−28N	−42B	−19N	+64B	−11N	+66B	+45N	=34N	−46B	3.5	34.5	36.0	9.75	1710	-1.8
53	Matsumoto, Yoshitaro	1966	JPN	+64N	−8B	+25N	F	F	=17B	=40N	=19B	−16N	3.5	33.5	33.5	14.50	1877	-16.2
54	Jones, StephenFM	2054	JPN	F	+47N	=36B	−37N	−57B	−20N	+62B	=46N	=48B	3.5	30.5	30.5	12.00	1700	-62.2
55	Miura, Yoshito	0	JPN	+27B	−18N	=43B	=24N	−17N	−26B	−56B	+64N	−47B	3.0	37.0	39.0	11.50	1725	0.0
56	Hasegawa, EmiWCM	1740	JPN	−31N	−32B	+65N	+42B	−39N	−11B	+55N	−43B	−45N	3.0	34.0	36.0	9.00	1729	-4.0
57	Takayasu, Melody	1721	JPN	F	−16B	−40N	+63B	+54N	−51B	+36N	−27N	−32B	3.0	32.5	32.5	10.00	1765	+6.4
58	Akeroyd, Peter	0	JPN	−37N	−38N	F	−19B	+61B	−36N	+64B	−25N	+63N	3.0	29.5	29.5	6.50	1717	0.0
59	Furuse, Mizuki	1677	JPN	−26N	−25B	+67N	−32B	−42N	−60B	+65B	+62N	−44B	3.0	29.0	30.5	5.50	1650	-12.4
60	Karasawa, Yuta	1740	JPN	−9B	+20N	−35B	−34N	−62B	+59N	−44B	−48N	=61N	2.5	33.5	35.5	9.75	1724	-5.0
61	Mitsuyama, RikkaWCM	1745	JPN	F	−13B	−45N	=51B	−58N	−64N	=67B	+66N	=60B	2.5	23.5	23.5	5.25	1710	-15.2
62	Terakawa, Toki	0	JPN	−43N	+19B	−17N	−25B	+60N	−42B	−54N	−59B	−65N	2.0	33.0	35.0	8.00	1599	0.0
63	Ono, Tadashi	1777	JPN	F	−22N	−50B	−57N	−20B	+65N	+66B	−32N	−58B	2.0	28.0	28.0	3.50	1689	-24.4
64	Hirukawa, Yoshitomo	1697	JPN	−53B	−34N	−47B	−52N	+67N	+61B	−58N	−55B	F	2.0	25.5	25.5	4.00	1680	-6.0
65	Itokazu, Antonio	1605	JPN	−39N	−46N	−56B	+67B	−33N	−63B	−59N	F	+62B	2.0	24.0	24.0	3.50	1482	-34.0
66	Yoshii, Yukihiko	1734	JPN	−30B	−36N	+20B	=46N	−47B	−52N	−63N	−61B	−67B	1.5	30.5	32.0	7.50	1546	-79.2
67	Kato, Ami	1799	JPN	−15B	−35N	−59B	−65N	−64B	F	=61N	−45B	+66N	1.5	25.0	25.0	2.75	1553	-43.8

Key insights

Biggest movers and upsets — the story behind the numbers.

Top rating gainers

1Noda, RyoJPN
+115.6
5.0 pts · #16
2Hashimoto, ShunjiJPN
+100.0
4.0 pts · #33
3Togawa, KentaroJPN
+89.2
5.0 pts · #27

Top rating losers

1Yoshii, YukihikoJPN
-79.2
1.5 pts · #64
2Moritani, ShoJPN
-63.6
4.5 pts · #26
3Jones, StephenFMJPN
-62.2
3.5 pts · #52

Biggest upsets

R2+379 Elo gap
Sato, Keito1664 beat Fujii, Chiaki2043
R5+333 Elo gap
Takayasu, Melody1721 beat FMJones, Stephen2054
R4+287 Elo gap
Noda, Ryo1756 beat Fujii, Chiaki2043