As the 2024-25 AFC Champions League Elite saw its first teams advancing to the knockout round from the East Region this week, the dominance of the tournament's Japanese contenders was clear for all to see.
Of the four teams to seal their last-16 berths, three were J1 League representatives with a duo doing so in style, while the third did not even need to be in action to progress.
Returning to continental action for the first time since retaining their domestic crown last December, Vissel Kobe brushed aside the weekend's Japanese Super Cup loss to Sanfrecce Hiroshima with an emphatic 4-0 rout of Shanghai Port.
Vissel looked completely in control from the time Yoshinori Muto opened the scoring after 11 minutes, before two goals early on in the second half by Yuya Kuwasaki and Koya Yuruki effectively ended the contest.
The Port defence, who looked lost at sea throughout the 90 minutes, went to sleep again with nine minutes remaining as Yuya Osako was left unmarked from a freekick to round off the scoring.
The result sealed a top-eight finish for Vissel and they were joined by compatriots Kawasaki Frontale, who beat Pohang Steelers by the same 4-0 scoreline.
Impressively, Frontale's comprehensive triumph came away from home and against a side still well in the hunt for a knockout round berth.
The victory bodes well for Frontale given they are looking to bounce back from a disappointing domestic campaign that saw them finish 8th in the J1 League, having won four titles in five years between 2017 and 2021.
In a sign that continuity might be key for Frontale this term, the majority of the side they fielded were all retained from last season with Shin Yamada -- who had a breakout campaign in 2024 with 19 goals in the league -- picking up where he left out as he opened the scoring against Pohang.
And while Yokohama F. Marinos were only in action against Shanghai Shenhua on Wednesday - which eventuated in a 1-0 triumph -- they too advanced with a game to spare a day earlier given there was no possibility they could fall out of the top eight.
It was nonetheless intriguing to see how Marinos shaped up following the offseason, with the only notable offseason arrival to feature being Colombian defender Jeisson Quiñónes.
However, Marinos -- also looking to bounce back from a poor campaign in 2024, where they finished 9th in the J1 League -- could employ a different system under long-time Chelsea and England assistant coach Steve Holland.
In only his second official head coaching job, Holland had Marinos deployed in a 3-4-2-1 formation that is increasingly trending in modern football.
One of the J1 League's most-damaging wingers for the past few seasons, Yan Matheus was instead fielded as one of two central attacking midfielders behind main striker Anderson Lopes -- and it was the duo who linked up for the former to bag the winner against Shenhua.
Given how Marinos had previously been characterised by their wing play, it will be interesting to see if others such as Élber can transition to a No. 10, while the likes of winger Kenta Inoue and right-back Ken Matsubara have already been asked to perform more-defensive and central roles respectively.
With all three of Japan's competitors through to the last 16, it will add a layer of intrigue over which other nations will be represented in the knockout round.
South Korea will boast Gwangju FC at the very least but will be hoping to be better represented, although Ulsan HD have been eliminated while Pohang are holding on to the 8th and final qualifying spot at present.
China, the third nation boasting three representatives, will have at least one team through but would have been hoping for more from the trio of Shandong Taishan, Port and Shenhua.
There remains a real chance that emerging nations such as Malaysia and Thailand are represented in the last 16 by Johor Darul Ta'zim and Buriram United respectively -- and it must be noted that both have previous history of getting to the knockout stage.
Doing so once again this season, at the expense of the traditional South Korean and Chinese powerhouses, will prove that those teams -- and their respective countries -- remain on the right track to upsetting the established order.
Or most of it anyway.
Because, for now, it is difficult to dispute Japan's dominance in the East.