Head-to-head · 13 bouts
Kasugao Katsumasa and Iwakiyama Ryuta have met 13 times in recorded sumo. Iwakiyama Ryuta leads 10–3.
Kasugao Katsumasa has won with: hooking inner thigh throw (1), underarm throw (1), frontal force out (1).
Iwakiyama Ryuta has won with: frontal force out (4), over arm throw (2), hand pull down (1), beltless armthrow (1), thrust down (1).
| Tournament | Day | Winner | Technique | Ranks |
|---|---|---|---|---|
| May 2001 | Day 8 | Iwakiyama Ryuta | Frontal force out | Makushita 38 East vs Makushita 31 West |
| September 2002 | Day 12 | Kasugao Katsumasa | Hooking inner thigh throw | Juryo 1 East vs Juryo 9 East |
| May 2003 | Day 2 | Iwakiyama Ryuta | Frontal force out | Maegashira 6 East vs Maegashira 9 West |
| July 2003 | Day 13 | Iwakiyama Ryuta | Frontal force out | Maegashira 10 East vs Maegashira 12 West |
| March 2006 | Day 11 | Iwakiyama Ryuta | Frontal force out | Maegashira 7 West vs Maegashira 3 West |
| May 2006 | Day 2 | Iwakiyama Ryuta | Hand pull down | Maegashira 8 East vs Maegashira 9 East |
| July 2006 | Day 14 | Iwakiyama Ryuta | Beltless armthrow | Maegashira 11 West vs Maegashira 10 West |
| September 2006 | Day 15 | Iwakiyama Ryuta | Over arm throw | Maegashira 15 West vs Maegashira 5 West |
| January 2007 | Day 10 | Iwakiyama Ryuta | Over arm throw | Maegashira 7 East vs Maegashira 10 East |
| January 2008 | Day 14 | Iwakiyama Ryuta | Thrust down | Maegashira 13 East vs Maegashira 11 West |
| March 2008 | Day 1 | Kasugao Katsumasa | Underarm throw | Maegashira 9 East vs Maegashira 9 West |
| May 2008 | Day 5 | Kasugao Katsumasa | Frontal force out | Maegashira 9 East vs Maegashira 11 East |
| September 2009 | Day 5 | Iwakiyama Ryuta | Frontal crush out | Maegashira 8 East vs Maegashira 11 West |
Every bout between the two that is in this database (March 1958 onwards). Technique names follow NHK WORLD-JAPAN.