Confirmed: The core facts are supported by the cited primary sources.
Open the ONE SAMURAI 3 MMA desk →Ito–Kurobe completes the card
ONE Championship announced on August 31 that former Pancrase flyweight champion Seiichiro Ito will face promotional newcomer Kazusa Kurobe in strawweight MMA at ONE SAMURAI 3. The promotion says the addition completes the mixed-discipline card scheduled for Saturday, September 12, at Yokohama Buntai.
Three MMA bouts are now verified
The official event page lists Yuya Wakamatsu against Willie van Rooyen at flyweight, Hiroba Minowa against Yuta Miyazawa at strawweight, and Ito against Kurobe at strawweight. Fight Atlas excludes the event's Muay Thai and kickboxing contests from its MMA-only desk.
No title designation
ONE does not advertise any of the three MMA contests as a championship fight. Fight Atlas has therefore added the complete MMA lineup without title markers or changes to fighter records, rankings or championship lineage.