Tochinoshin was the surprise winner of the January tournament
6: The highest ranked referee, Shikimori Inosuke, is reported in the Japanese media to have apologized for sexually harassing a junior referee in a hotel in Okinawa Prefecture on December 16 last year, while drunk.
14: The Sumo Association suspend Shikimori Inosuke for three tournaments. He has already submitted his resignation, but it will not take effect until after the suspension ends in May 2018. With the other top referee title (Kimura Shonosuke) currently vacant, this will be the first time since the March 1994 tournament that neither of the head referees (tate-gyōji) will be available.
11: Kakuryū and Kisenosato, both of whom have missed some or all of the preceding four tournaments, each confirm that they will enter the forthcoming Hatsu basho.
22: Egyptian juryo division wrestler Ōsunaarashi withdraws from the tournament after reports emerge that he was involved in a rear-end motor collision at the Yamanouchi, Nagano ski resort town on January 3. Osunaarashi apparently defied the Sumo Association's ban on wrestlers driving cars, and also did not have a valid licence. He initially told police that his pregnant wife was driving and he switched seats to protect her, but back-tracked when confronted with security video evidence.
25: A lawsuit against Kasugano Oyakata and a former member of Kasugano stable who had been convicted of assault, is publicly revealed for the first time. The victim, another former wrestler from the stable, alleges that Kasugano failed to prevent the attack and delayed medical treatment.
28: On the final day of the Hatsu Basho, Tochinoshin wins again to finish on 14–1, two wins ahead of ōzekiTakayasu on 12–3. Kakuryū, the only yokozuna to complete the tournament, stops a run of four straight defeats by beating ōzekiGōeidō to finish with a respectable 11–4 record on his comeback. Tochinoshin receives special prizes for Outstanding Performance and Technique to go with his first Emperor's Cup, while the Fighting Spirit Award is shared between top division debutants Ryūden and Abi, who both score 10–5. The jūryō division championship is won by Myōgiryū for the third time, after a playoff with Hidenoumi. Retiring this tournament are former maegashiraShōtenrō, Kitataiki and Sōtairyū [ja].
31: Seven promotions to the jūryō division for the March tournament in Osaka are announced. There are two newcomers, Enhō (who ties the record for fastest postwar promotion to jūryō at six tournaments) and Takayoshitoshi (meaning he and Takagenji have become the first identical twins to both be ranked as sekitori) while Yago, Terutsuyoshi, Shimanoumi, Tobizaru and Akiseyama return.
The 40th Shikimori Inosuke was suspended in January
2: Elections to the 10 man Board of Directors of the Japan Sumo Association are held. Isegahama Oyakata (ex-Asahifuji) and Nishonoseki Oyakata (ex-Wakashimazu) do not run for re-election. The eleven candidates running are Kasugano, Sakaigawa, Dewanoumi and Yamahibiki from Dewanoumi ichimon, Oguruma and Shibatayama from Nishonoseki ichimon, Kagamiyama from Tokitsukaze ichimon, Hakkaku from Takasago ichimon, Takashima from Isegahama ichimon, and Takanohana and Ōnomatsu from Takanohana ichimon. The man to miss out is Takanohana, who receives only two votes from the 101 elders who participated. He had been dismissed from the board at the end of December following his lack of co-operation with the Sumo Association's investigation into the Harumafuji assault on Takanoiwa last year.
4: Former sekiwakeAsasekiryū, who retired last May, has his danpatsu-shiki at the Kokugikan. He is now officially Nishikijima Oyakata.
8: An outside committee led by a former prosecutor general, Keiichi Tadaki, is formed and will interview all 900 wrestlers in the Sumo Association in response to a series of incidents since Harumafuji's retirement. Tadaki says, "Our goal is the preservation of sumo. It is important to grasp the reality."
11: The 42nd Fuji TV Grand Sumo Tournament takes place at the Kokugikan. A knock-out format exhibition with a 2,500,000 yen prize for the yusho, it is won by Tochinoshin who defeats Ikioi, Hakuhō (who he has never beaten in official competition in 25 attempts), Hokutofuji, Okinoumi and finally Tamawashi.
9: Ōsunaarashi is asked to retire by the Sumo Association over his involvement in the vehicle collision and driving without a license. He had been fined 500,000 yen ($4700) by a court over the incident in Nagano Prefecture in January. Ōsunaarashi agrees to the request.
18: New juryo Takayoshitoshi withdraws from the Osaka tournament after admitting he struck a junior wrestler who was acting as a personal attendant several times in the dressing room after his Day 8 bout. Takayoshitoshi was reportedly angry that the attendant had not informed him when he was due to enter the arena, making him late for his match.
23: Takanohana indicates that he will drop his legal complaint against the Sumo Association and admits responsibility for Takayoshitoshi’s behavior, as his stablemaster.
25: On the final day Takayasu defeats Kakuryu after a re-match to finish one win behind the yokozuna on 12–3. Kakuryu had clinched his fourth championship the previous day, and his only other defeat was to Tochinoshin, who wins the Outstanding Performance Award. Brazilian Kaisei is a surprise joint runner-up with Takayasu on 12–3 and wins the Fighting Spirit Prize. The Technique Award goes to Endō, who for the first time gets a winning record at the top maegashira rank. The jūryō championship is won by Sadanoumi after a playoff with Akiseyama while veteran Higonojō [ja] takes the makushita title. Retiring is Kotomisen [ja], who spent two tournaments in jūryō in 2013.
29: Takanohana is demoted two further ranks in the Sumo Association hierarchy, to the lowest rank of toshiyori. Takayoshitoshi is suspended from the next tournament in May.
4: Maizuru, Kyoto Prefecture. Chairman Hakkaku issues an apology after a referee ordered women off the dohyo when they were trying to administer first aid to the mayor of Maizuru, who had just collapsed with a subarachnoid hemorrhage while giving a speech. Hakkaku says, "In a situation that could have been life-threatening it was an inappropriate response."
6: Takarazuka, Hyogo Prefecture. The female mayor of Takarazuka, who had to stand next to the dohyo instead of entering it at the exhibition, meets with the Sumo Association's public relations chief Shibatayama on April 18, and asks that they reconsider the longstanding "no women" policy.
28: At an extraordinary meeting of its board, the Sumo Association clarifies that women can enter the dohyo in an emergency situation and will consider outside opinions from experts and members of the public over whether its ban should be overturned.
11: Former maegashira Ōiwato [ja] announces his retirement. Last year he became the oldest winner of the makushita division championship in the six tournaments a year era. He plans to work for an electronic recycling company in Kanagawa Prefecture.
11: The Tagonoura stable duo of Kisenosato and Takayasu both announce they will miss the beginning of the May tournament. For Kisenosato it will be the seventh straight basho he has failed to complete, equaling the unwanted record of most yokozuna absences post-1958 set by Takanohana who sat out seven full tournaments in 2001 and 2002. Takanohana did make a successful comeback with a 12-3 record in September 2002 and tells Kisenosato, "He should take his time to heal. As long as he's fighting he should be in top shape. The key is not to rush." Kisenosato's stablemaster Tagonoura says doctors have told the yokozuna he should stay away from intense training for a month, and will "fight for his life" when he next competes in July. Takayasu injured his left upper arm in training earlier in the week but still hopes to enter the tournament at some point.
14: Former maegashiraAmūru of Russia, who has fallen to makushita, announces his retirement.
21: The only ōzeki competing in the May tournament, Gōeidō, pulls out with an ankle injury, making this the first time since 1949 that the only two ōzeki on the banzuke have withdrawn from a tournament.
27: The championship is decided in the final bout of the tournament, with Kakuryū defeating Hakuhō to clinch his second successive yūshō with a 14–1 record, avoiding the need for a playoff with Tochinoshin, who finishes on 13–2. Tochinoshin wins the Technique and Fighting Spirit Prizes, and with 37 wins over the last three tournaments is assured of ōzeki promotion. Also sharing the Fighting Spirit Prize are Kyokutaisei, who scores 10–5 in his makuuchi debut, and Chiyonokuni, who produces his best ever record of 12–3. The Outstanding Performance prize goes to Shōhōzan, who is the only man to defeat Kakuryū. In the jūryō division former komusubiŌnoshō comes back strongly from injury to take the championship with a 12–3 record. Retiring along with the previously announced Ōiwato and Amūru is former jūryō Masakaze who is suffering from illness.
7: Police say that Takayoshitoshi has been reported to prosecutors in the case over striking his attendant. He has already reached an out of court settlement with the victim.
25: The rankings for the Nagoya tournament in July are released, with Tochinoshin listed as ōzeki for the first time. Both of his fellow ōzeki, Gōeidō and Takayasu, are kadoban (in danger of demotion). There are two newcomers to the top division, Kotoekō [ja] and Meisei [ja], with Ōnoshō returning.
2: Kisenosato faces fellow yokozuna Hakuhō in a training session (degeiko) at Kokonoe stable, the first time the two have sparred in over a year.
5: Kisenosato announces that he will miss the forthcoming Nagoya basho, making it the eighth straight tournament he has failed to complete. This is a record for a yokozuna.
13: Kakuryū withdraws through injury on Day 6 of the Nagoya tournament, joining Hakuhō who pulled out on Day 4 and Kisenosato who was absent from the beginning. It is the first time since 1999 that all three yokozuna have failed to complete a tournament.
14: Tochinoshin is forced to withdraw from his debut tournament as an ōzeki due to a toe injury suffered in the previous day's bout. He had won his first five matches, but will now be kadoban in the September tournament.
21: Mitakeumi wins his first championship by defeating Tochiozan on Day 14 which gives him a 13–1 record and an unassailable two win lead going into the final day. He is the first wrestler from Dewanoumi stable to win a top division championship since 1980, and also the first Japanese wrestler born in the Heisei era to do so.
22: Mitakeumi is defeated on the final day by Yutakayama and finishes on 13–2, but also wins special prizes for Outstanding Performance and Technique. Yutakayama is the runner-up on 12–3 and shares the Fighting Spirit prize with Asanoyama, who finishes on 11–4. The juryo championship is won by Takanoiwa, who is set to return to makuuchi for the first time since his assault by Harumafuji. The makushita championship is won by Hakuyozan, and the sandanme title goes to former maegashiraKagamio.
The summer tour visits the following locations:
21: Akita, Akita Prefecture. Takanohana is taken to hospital after suffering convulsions and falling unconscious while supervising a morning training session in the city. He is discharged the following day.
27: The banzuke for the upcoming Aki basho is released. Tochinoshin is in danger of demotion in only his second ōzeki tournament. Mitakeumi is East Sekiwake, his 10th straight tournament in sanyaku.Kotoyuki returns to makuuchi for the first time since March, while Takanosho [ja], a 23 year old from Chiganoura stable, makes his top division debut.
7: The matches for the first two days are announced, with all 70 sekitori expected to participate in the tournament. Kisenosato is paired against Ikioi on Day 1, who he has lost to only once in his career.
12: Day 4 sees three yokozuna all undefeated, the first time this has happened since the March 1989 tournament when Chiyonofuji, Hokutoumi and Onokuni were all 4–0.
22: Hakuhō marks his return from injury by defeating Goeidō to claim both his 41st championship and his 1000th win in the top division.
23: Hakuhō defeats Kakuryū (handing him his fifth straight loss in the tournament) to ensure a zensho-yusho, the 14th of his career. Kakuryū drops to 10-5, the same score as Kisenosato, who secures a majority of wins for the first time since his yokozuna debut in March 2017. Goeidō is the runner-up on 12–3, while his fellow ōzeki Takayasu and Tochinoshin finish on 11-4 and 9–6 respectively, the latter preserving his ōzeki status. There are no special prizes awarded for the first time since the sansho system was introduced in 1947. The jūryō championship is won by Tokushoryu who defeats Daiamami in a playoff after both wrestlers finish on 11–4. Ōrora, the heaviest sumo wrestler ever at 292 kg (644 lb), announces his retirement after 18 years in sumo.
25: The promotions to the jūryō division for the next tournament in Kyushu are announced. There are two newcomers: Gokushindo [ja] of the Nishikido stable and Oguruma stable's Tomokaze [ja]. Returning after two years in makushita is former sekiwakeToyonoshima.
19: The panel set up in February in the wake of the Harumafuji assault presents its report to the Sumo Association and calls for mandatory reporting and disciplinary measures for acts of violence within stables.
19: The rankings for the Kyushu tournament next month are released. There are no newcomers to the top division but Daiamami, Meisei and Arawashi all return. Kaisei returns to the sanyaku ranks for the first time since September 2016. Veteran Gagamaru is demoted to the makushita division.
8: Hakuhō and Kakūryū both announce that they will miss the forthcoming November tournament through injury, meaning Kisenosato will be the sole yokozuna participating.
15: Kisenosato withdraws after losing his first four matches, reporting a right knee injury.
25: The tournament is won by komusubiTakakeisho, who defeats Nishikigi to finish with a 13-2 record. Ōzeki Takayasu fails to force a playoff after being defeated by Mitakeumi, and must settle for 12-3 and runner-up honours. It is Takakeisho's first top division championship in just his 26th career tournament, the 6th fastest since 1958 alongside Akebono. He is the third first-time yusho winner of the year, the most since 2000. He receives prizes for Outstanding Performance and Fighting Spirit. Ōnoshō also shares the Fighting Spirit prize after winning his tenth bout. Tochinoshin finishes on 8-7, which is enough to give him the most victories in makuuchi in 2018, with 59. (No wrestler managed a winning record in every tournament in the top division in 2018.) The juryo division championship is won by Tomokaze in his juryo debut with a 12-3 record, from the very bottom rank of #14 West. Veteran Sokokurai wins the makushitayusho. Former maegashiraSatoyama retires at the age of 37 and becomes Sanoyama Oyakata.
28: The makushita division wrestler Shingaku retires after he was involved in a car accident on November 10 and charged with being under the influence of alcohol and failure to report an accident. His stablemaster Ōtake Oyakata is punished by the Sumo Association with a 20 percent salary cut for the next six months.
The winter tour visits the following locations:
5: Takanoiwa is suspended from the winter tour by the Sumo Association after he assaulted his tsukebito or personal attendant, reportedly because "he made an excuse for forgetting something." Takanoiwa was himself assaulted in October last year by now retired yokozunaHarumafuji. Shibatayama Oyakata comments, "Takanoiwa is supposed to understand the (pain) the most...We will take strict action over this incident."
7: Takanoiwa retires, submitting his letter of resignation to the Sumo Association, to take responsibility for the incident.
1 Jan: Former maegashira 1 Katsuhikari, also former Wakafuji Oyakata, aged 75, of cancer.