Kashima finished 15 points behind Urawa Reds in the regular season, lost the home leg of the championship final 1-0 and went a goal down in the second leg but still pipped their rivals to the title with a 2-1 win on Saturday.
Mu Kanazaki's brace gave them a first league crown since 2009 and also earned them a maiden berth at the Club World Cup.
Kashima open their campaign just five days after their Saitama triumph against New Zealand's Auckland City in Yokohama on Thursday but manager Masatada Ishii said he was certain they would give a good account of themselves.
"We want to give a good performance as the J-League representatives and reach the final," he told a news conference on Monday.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"There might be fatigue but I can feel the excitement heightening. We've switched mentally. We'll aim to fight like Japanese champions."
Kashima are Japan's most successful clubs with those eight league titles, a record six J-League Cups, four Emperor's Cup triumphs and a perennial presence in the top half of the J-League.
Their success has had a distinctly Brazilian flavour with nine of their 13 managers having coming from the South American country, including Zico, Edu and Oswaldo de Oliveira, who masterminded a domestic title hat-trick from 2007-2009.
Ishii is the first Japanese manager to win the J-League with the club.
Kanazaki, who scored 13 goals from 33 matches in the just-concluded campaign, is clearly Kashima's main strike threat but it is a collective big match temperament that has served the club so well over the years.
While that has proved to be the case on home soil, they have rarely thrived in international competition and a single quarter-final appearance is their best finish in six Asian Champions League campaigns.
(Writing by Nick Mulvenney in Sydney, editing by Peter Rutherford)
