Nihon Sumo Kyokai

No closed-fist punches (open-hand slaps permitted); No kicking; No grabbing hair

82 officially recognized winning techniques (kimarite) — including yorikiri (force-out grip), oshidashi (push-out), uwatenage (overarm throw), shitatenage (underarm throw), various trips + lifts + slap-downs; Each match victory recorded with the kimarite used — kimarite history is preserved as pa...

No fixed time limit — matches typically last 5-30 seconds; most are over within 10 seconds; Pre-match ritual (shikiri) takes 4+ minutes; salt-throwing + facing-off; the actual bout is brief

Mawashi (silk belt loincloth): the rikishi's only attire during competition; ~9-13 m long, folded + wrapped around the waist + crotch; color varies by rank (Makuuchi: vibrant colored; lower divisions: black cotton); Chonmage (topknot hair-style): traditional samurai-style hair worn by all profess...

Dohyo (土俵): elevated clay-and-sand ring, raised ~50 cm above the floor; Inner ring diameter: 4.55 m bounded by a circular rope (tawara) embedded in the clay; Outer dohyo platform extends an additional ~2 m beyond the rope

Two rikishi per match (1-on-1); No weight classes — all rikishi within a division compete open-weight; Divisions (highest to lowest): Makuuchi, Juryo, Makushita, Sandanme, Jonidan, Jonokuchi, Maezumo

No fixed time limit — matches typically last 5-30 seconds; most are over within 10 seconds; Pre-match ritual (shikiri) takes 4+ minutes; salt-throwing + facing-off; the actual bout is brief; Force opponent out of the dohyo (any part of body steps outside the rope), OR

Each match: 1 win or 1 loss recorded per rikishi (no scoring beyond W/L); Each basho: 15 days × 1 match per rikishi = up to 15 wins; Kachi-koshi: 8 or more wins in a 15-day basho = winning record (promotion + bonus)

Banned technique (kinjite): immediate loss + potential commission discipline; Mawashi failure (belt comes off during match): immediate loss (rare, considered dishonorable); Premature start (henka jump): tactical move (not technically illegal) but heavily frowned upon at Yokozuna rank

Professional sumo's injury profile: severe limb fractures (especially knees), neck injuries from being thrown, shoulder + back strain from grappling at high body weights (rikishi often 130-200+ kg)...