On September 9, four men, including Shun'uo Kusuno, the leader of the Narashino family affiliated with the Inagawa-kai Yakuza group, were arrested for trespassing in Tokyo Dome during a Giants baseball game. The Tokyo Dome has a strict prohibition against the entry of gang members, as indicated by signage, and the suspects allegedly entered the premises around 5:10 PM on September 10 to watch the game between the Giants and the Hiroshima Carp.

According to police sources, the suspects were spotted by stadium personnel due to their tattoos, which led to them being reported to the authorities before they left the area around 7 PM. Notably, the tickets for the season seats they used were allegedly purchased under the name of a waste management company based in Chiba. This incident raises concerns regarding ongoing issues with organized crime infiltrating sports events, as similar arrests have occurred in the past.

Since the enactment of the "Gangs Exclusion Declaration" in 2003, professional baseball leagues in Japan have implemented strict regulations against gang member attendance, which are reinforced through both contracts and well-publicized policies on the venues' websites. This ongoing matter reflects the sports community's efforts to distance itself from organized crime, underlining the significance of maintaining a safe and family-friendly environment at sporting events.