Hokuseihō Osamu (北青鵬 治, born 12 November 2001 as Ariunaagiin Davaaninj (Mongolian: Ариунаагийн Даваанинж[2]) is a former sumo wrestler from the Miyagino stable.

After the January 2024 tournament, allegations of assaults by Hokuseihō against fellow rikishi in his stable led to an investigation by the Sumo Association,[4] which later verified them.

[5] On 22 February 2024, the day before the full Sumo Association board met to take up the committee's recommendations, Hokuseihō submitted his retirement notification.

[8] On his way to a temporary return trip to Mongolia he met yokozuna Hakuhō by chance at an airport in South Korea, who encouraged him to try sumo.

Although born in Mongolia, as he had been residing in Japan since five years old, he was able to obtain Japanese nationality and so did not need Miyagino's one foreigner spot (sumo rules allow for only one foreign-born wrestler per stable).

[12] There he made his debut at the same time as Shishi, the first Ukrainian to join professional sumo, and Hōzan Takamori [ja], the second son of former sekiwake Takatōriki and older brother of Ōhō.

[15] Upon his return in March 2021 he lost his first bout in professional sumo to Tokisakae to bring his winning streak to an end, but recovered to post a 5–2 record.

On the final day of the tournament, however, Hokuseihō was defeated by ōzeki Hōshōryū, effectively taking him out of the title race and removing his hopes of receiving the award.

Further details later emerged that for over a year Hokuseihō had mistreated other wrestlers by striking them with sticks made from pieces of mawashi and abusing them using a combination of insecticides and burners.

"[42] Despite the circumstances that led to his departure from the Sumo Association, it has been pointed out by several sources that Hokuseihō wanted to hold a haircutting ceremony in April.

[43] As of August 2024, however, it was reported he had not yet cut his chonmage, on the occasion of his first public appearance after the scandal when he attended a training session at Arashio stable.

[44] At 204 cm (6 ft 8 in) Hokuseihō was the tallest sekitori during his professional years,[1] and with his big height advantage he was able to overwhelm most of his early opponents by quickly grabbing their mawashi and forcing them out of the dohyō.

[39] In the run-up to the Nagoya tournament in July 2023, he also confided that he was beginning to practise pushing and thrusting techniques (tsuki/oshi) in order to diversify his fighting style, taking particular inspiration from the matches of former yokozuna Akebono.