The White Swans have appointed from within their own structure, selecting 37-year-old Okuyama who has had a 14-year history with the club
Tatsuyuki Okuyama, who was part of the coaching setup at the White Swans this year, will be the new Head Coach for the 2014 season.
Okuyama has been with Albirex Niigata in Japan since 1999, starting out as a coach in the club's football academy before leading various youth teams at the club from 2005 to 2007.
Prior to his arrival in Singapore this year, he was Head Coach of the Albirex Niigata Ladies team from 2008 to 2012.
The 37-year-old holds a JFA 'A' coaching license and spoke about improving the team, via the club's official website.
"I would like to thank our sponsors, supporters, club staff, team staff and S.League for this opportunity," said Okuyama.
"I will do my best to make team even better for the season 2014."
Sugiyama, who was the club's longest serving coach having been appointed in 2010, is also the only coach to have won a title in the club's 9-year presence in the S.League. He won the 2011 League Cup in a successful season that also saw him winning the Coach of the Year honours at the S.League Awards Night. He departs following the end of his contract and the 42-year-old is believed to be interested in staying in the S.League.