The following are the events in professional sumo during 2010.
Tournaments
Hatsu basho, Ryogoku Kokugikan, Tokyo, 10 January – 24 January
Haru basho, Osaka Prefectural Gymnasium, Osaka, 14 March – 28 March
Natsu basho, Ryogoku Kokugikan, Tokyo, 9 May – 23 May
Nagoya basho, Aichi Prefectural Gymnasium, Nagoya, 11 July – 25 July
Aki basho, Ryogoku Kokugikan, Tokyo, 12 September – 26 September
Kyushu basho, Fukuoka International Centre, Kyushu, 14 November – 28 November
News
January
12: At the Hatsu basho in Tokyo, ozeki Kaio wins his 808th top makuuchi division bout by throwing down former ozeki Chiyotaikai, breaking the record set by Chiyonofuji in 1991. It is Chiyotaikai's third defeat in the first three days, leaving his hopes of getting promoted back to ozeki by scoring 10–5 or better virtually gone. 13: Chiyotaikai announces his retirement from sumo. He will stay in the sumo world as a coach at Kokonoe stable, under the name Sanoyama Oyakata. 19: The 65th Yokozuna Takanohana is told to leave the Nishonoseki ichimon or group of stables after announcing that he will run for a position on the board of Directors of the Japan Sumo Association against the two officially sanctioned candidates for the group. Six of Takanohana's supporters, Otake (the former Takatoriki), Futagoyama (the former Dairyu), Otowayama (the former Takanonami), Tokiwayama (the former Takamisugi), Onomatsu (the former Masurao) and Magaki (the former Wakanohana II), are also kicked out of the ichimon. 23: Yokozuna Asashoryu wins his 25th yūshō or championship by defeating ozeki Harumafuji by shitatenage or underarm throw. His score of 13 wins against just one loss means he cannot be caught by any of his rivals. He is now alone in third place on the all-time list of top division championships, behind only Taiho and Chiyonofuji. 24: On the final day of competition, Hakuho defeats Asashoryu to finish runner-up to his yokozuna rival on 12–3. Having lost only four regulation bouts in the whole of 2009, his three losses in this tournament (to Baruto, Harumafuji and Kaio) are the most he has suffered since May 2008. Baruto also finishes on 12–3, and wins his first Outstanding Performance Award. Had he achieved kachi-koshi, maegashira Goeido would have received a share of that prize as he defeated Asashoryu earlier in the tournament, but he loses to Aminishiki who receives the Technique Award. The third man on 12–3 is Toyohibiki, who wins the Fighting Spirit Prize. The jūryō division championship is won by Georgian Gagamaru. Two former maegashira who have been fighting in the third makushita division for some time, Tamarikido and Daimanazuru, both announce their retirements. Tamarikido is staying in sumo as Araiso Oyakata, but Daimanazuru is leaving. 25: Asashoryu is warned over his conduct by Sumo Association head Musashigawa after reportedly punching one of his managers during a drunken night out after Day 6 of the basho. 27: The promotions to the jūryō division for the Haru tournament in March are announced. There are three newcomers: (formerly Kurosawa, his new shikona is based on that of his stablemaster, the former Masurao) and Daido (formerly Nakanishi), both from the Onomatsu stable, and Sadanofuji from the Sakaigawa stable. In addition, Tokushinho from Kise stable returns to the jūryō division after two tournaments away. 28: The weekly magazine Shukan Shincho hits the newsstands and claims that the man allegedly assaulted by Asashoryu was not his manager but another acquaintance in charge of a dance club where Asashoryu was drinking, who received a broken nose. Amid suggestions of a cover-up, the Sumo Association demand an explanation. 30: Musashigawa says that Asashoryu has reached an amicable settlement with the man he allegedly attacked, meaning the yokozuna will not face police charges, although the chairman has not seen written confirmation. He confirms that any punishment will not be decided on until the next board meeting on February 4. 30: The danpatsu-shiki or retirement ceremony of former maegashira Otsukasa takes place at the Kokugikan. 31: The retirement ceremony of former maegashira Ushiomaru is held at the Kokugikan. Asashoryu performs the dohyo-iri and takes a snip of Ushiomaru's hair.