By SABC Sport
14th July 2024
The 24-year-old right-back joins from Dutch club AZ Alkmaar, where he played nearly 200 first-team games after joining from Japanese club Nagoya Grampus in 2018.
"To come to Southampton and to play in the Premier League is one of my biggest dreams since I was young, so I am really excited to be here," the 13-times capped Sugawara told the Saints website.
"I felt Southampton is a really good club. When Southampton gave me an offer, I said yes after one second."
Former Saints, Arsenal and Aston Villa defender Calum Chambers has joined Sky Bet Championship club Cardiff.
The 29-year-old, who won three caps for England in 2014, has signed a three-year contract with the Bluebirds after leaving Villa earlier this week.
"I'm absolutely delighted, and I can't wait to get started," said Chambers.
"I'm at a stage in my career where I want to be ambitious and create memories for myself as well. It was a good time for us both to meet at this point."