19: The 48th yokozunaTaihō, winner of a record 32 tournament championships, dies aged 72.[8][9] He is generally regarded as the greatest sumo wrestler of the post-war period.[10]
27:
YokozunaHarumafuji takes his fifth top division championship with a perfect 15–0 record, defeating fellow yokozunaHakuhō who finishes on 12–3, having also lost to maegashiraMyōgiryū and ōzekiKotoōshū.[11]
Former maegashiraBushūyama and former komusubiTakamisakari announce their retirements. Takamisakari will stay in sumo as a coach at his Azumazeki stable under the name "Furiwake".[12][13]
28: The Japan Sumo Association announces the Nishonoseki stable's closure. Coaches Kitajin and Minatogawa transfer to the Matsugane stable, while coach Fujigane transfers to the Kasugano stable, and Nishonoseki's remaining three wrestlers retire.[14]
30: The spring tournament banzuke organization meeting is held. Tochihiryū makes his jūryō debut, while Oniarashi and Senshō return to the same rank from makushita.[15]
22: On the 13th day of the spring tournament, yokozuna Hakuhō defeats Gōeidō to earn a 13–0 record, and his championship victory is assured when Okinoumi is defeated. It is the fourth time that he has won a top division championship by the 13th day, a record for the 15-day tournament era that he shares with Chiyonofuji.[19]
24:
Hakuhō, already determined to be the championship victor, defeats Harumafuji and wins a record ninth perfect victory.[20]
Former ōzekiMiyabiyama retires after facing demotion to makushita. He will remain in sumo as a coach at his Fujishima stable, under the name "Futagoyama".[21]
25: The Tokyo District Court rules that the former wrestler Sōkokurai was wrongly dismissed in April 2011 over match fixing allegations. Sōkokurai says, “Let me return to the sumo ring.” The Sumo Association is considering whether to appeal the ruling.[22]
1: The Japan Sumo Federation transitions into a public juridical foundation.[23]
3: The Sumo Association announce that they will accept Sōkokurai's return, and that he will appear on the July banzuke at maegashira #15, his last rank before he was thrown out of sumo.[24]
25: The banzuke for the forthcoming May basho is released. Daikihō, Chiyoōtori, Homarefuji and Azumaryū make their makuuchi debut, with Kyokushūhō returning. Okinoumi is promoted to komusubi, becoming the first new san'yaku wrestler from Shimane Prefecture in 121 years.[25]
21: On the 10th day of the summer tournament, Hakuhō defeats Gōeidō and sets a record for the highest amount of consecutive double-digit winning records at 38.[26]
26: Hakuhō's 25th championship victory is claimed when Kisenosato is defeated by Kotoshōgiku. Hakuhō then defeats Harumafuji and wins his tenth perfect championship.[27]
A banzuke meeting is held in Nagoya. Seirō, Kotomisen, Endō and Ōsunaarashi make their jūryō debut. Endō reached this division in two tournaments, while Kotomisen reached it in 86, the fourth slowest climb in history. Egyptian Ōsunaarashi is the first African sumo wrestler.[29][30][31][32]
9: Former yokozunaKitanoumi performs his kanreki dohyō-iri at the Ryōgoku Kokugikan. He is the ninth person to perform the kanreki dohyō-iri, and the fourth to do so while serving as the Japan Sumo Association's chairman.[34]
20: The Japan Sumo Association announces the retirement of stablemaster Nishonoseki, who was hospitalized in October 2012 following a stroke, and would have reached the mandatory retirement age in the upcoming November.[35]
13: Hakuhō defeats Chiyotairyū on the 7th day of the Nagoya basho, becoming the first wrestler since the Showa era to obtain a consecutive winning streak of 37.[36]
19: Hakuhō defeats Kotoōshū on the Nagoya basho's 13th day, and with a winning record of 13–0, Hakuhō's 26th championship victory is assured. This 26th victory is the third highest amount in sumo, and the highest for a foreign-born wrestler. It is also the first time since the introduction of 15-day tournaments that the victors of all divisions were decided on the 13th day.[37]
20:
Hakuhō loses to Kisenosato on the Nagoya basho's 14th day, ending his winning streak at 43.[38]
Former jūryō Mutetsuyama, director of Toyo University's Ushiku High School Sumo Club, dies of heart failure in his home at 42.[39]
24: Terunofuji (formerly Wakamishō) and Chiyomaru are promoted to jūryō. Chiyomaru is the brother of Chiyoōtori, becoming the 17th pair of sekitori brothers.[40]
2: The banzuke for the autumn tournament is released. Endō makes his makuuchi debut in three tournaments, the fastest climb since the Showa era. Takayasu is promoted to komusubi, becoming the first new san'yaku wrestler to have been born in the Heisei era.[43]
11: Former ōzekiBaruto announces his retirement after missing the last two tournaments due to injury.[44]
12: The Tokyo District Court dismisses Kotomitsuki's lawsuit against the Sumo Association for wrongful dismissal relating to his involvement in a baseball gambling ring.[45]
27: On the 13th day of the autumn tournament, Tenitsu is deemed the victor of the sandanme division. At 35 years and 10 months old, he is the oldest post-war wrestler to win a tournament under the makushita division.[46]
28:
On the 14th day of the autumn tournament, Hakuhō defeats Kisenosato and claims his 27th championship victory.[47]
Former jūryō Toyonokuni announces his retirement.[48]
29: Terunofuji claims the jūryō title with a score of 12–3 in his division debut.
8: Former sekiwakeAran, who had transferred from the Mihogaseki stable to the Kasugano stable on the 3rd, announces his retirement due to his poor physical condition, and returns to Russia to become a businessman.[51]
31: A new discipleship inspection is conducted in Kyūshū, and five people, including Mongolian Altankhuyag Ichinnorov, pass. Ichinnorov, taking on the name Ichinojō, becomes the first foreign wrestler to debut at an elevated rank in the makushita division due to his success in amateur sumo.[52]
2: The National Student Sumo Championship is held. Kohei Ichinose of Nippon Sport Science University defeats Ryota Koyanagi of Tokyo University of Agriculture in the final match.[53]
3: A team competition of the National Student Sumo Championship is held, and Toyo University defeats Kindai University with 3 wins and 2 losses in the final match, achieving their third victory in 11 years.[54]
8: The concurrent stablemaster of Kasugayama stable, former maegashiraHamanishiki, announces that he will file a proceeding against the preceding stablemaster, former maegashiraKasugafuji, to hand over control of the elder stock.[55]
11: On the second day of the Kyūshū tournament, Hakuhō defeats Aminishiki, becoming the fourth wrestler to achieve 500 wins as yokozuna. Within 38 tournaments, he achieved this milestone in the shortest time. He also achieves the most wins for a wrestler in 2013.[56]
13: Former yokozunaTakanohana steps in as acting director of the Isegahama stable due to the hospitalization of its stablemaster, former yokozunaAsahifuji.[57]
17: On the 8th day of the Kyūshū tournament, Hakuhō defeats Takekaze, achieving 700 total wins in the fastest time.[58]
19: On the 10th day of the Kyūshū tournament, Hakuhō defeats Tochinowaka and achieves 38 consecutive double-digit winning records as yokozuna, the highest in history.[59]
20: On the 11th day of the Kyūshū tournament, Hakuhō defeats Tochiōzan and achieves 80 wins in a year for the third time in history.[60]
24:
Harumafuji defeats Hakuhō and wins his sixth makuuchi tournament with a 14–1 record.[61] Hakuhō's consecutive championship-winning streak is ended at four, and his consecutive Kyūshū championship-winning streak is ended at six.[62]
The Yokozuna Deliberation Council indicate that Kisenosato will have to capture the title with at least 13 wins in the next basho to earn promotion to sumo's highest rank.[63]
27: The banzuke meeting for the New Year tournament is held. Mongolian Sakigake makes his jūryō debut after 62 tournaments, the third slowest climb for a foreign wrestler, and four other wrestlers return to the rank from makushita.[64]