The 29-year-old announced on his blog that he penned a deal last week after two seasons with rivals Lierse SK.
"Standard are always one of the top contenders in Belgium and their supporters are the most enthusiastic," said Kawashima, who was out of contract at Lierse and had been looking to move on.
"I'd been thinking what is the best way for me and I decided this is the most suitable for my life," he said. "It was a big challenge to play two years for Lierse and this is another new step forward. I feel happy about it."
Kawashima wrested the regular starting position in the national team from Seigo Narazaki shortly before the 2010 FIFA World Cup™ in South Africa and helped Japan win the AFC Asian Cup for a record fourth time in January last year.