Suzuki arrives from Parma in a deal worth around 30 million pounds, while Ruggeri has joined from Atletico Madrid in a package that could rise to approximately 21 million pounds.
The 23-year-old Suzuki is regarded by Villa as a potential long-term successor to Emiliano Martinez, adding further uncertainty to the Argentina international's future at the club.
Martinez's proposed move to Juventus collapsed over the weekend after the two clubs failed to reach an agreement on a fee. The goalkeeper remains at Villa for now, having played a key role in their Europa League triumph in May and Argentina's 2022 World Cup route to the final where they fell at the final hurdle to Spain.
Suzuki spent the past two seasons with Parma, making 59 appearances after previously playing for Urawa Red Diamonds and Belgian side Sint-Truiden. Born in the United States, he became a full Japan international and is set to become the first Japanese goalkeeper to play in the Premier League.
Ruggeri, meanwhile, has been brought in to fill the void left by Lucas Digne, who joined Paris Saint-Germain earlier this month.
The 24-year-old left-back developed at Atalanta and made more than 100 appearances for the Italian club, helping them win the Europa League in 2024 before moving to Atletico Madrid. He made 47 appearances in all competitions for Diego Simeone's side last season.
Ruggeri has represented Italy through Under-21 level and has received senior call-ups but is yet to make his full international debut.
Both new arrivals could be involved when Villa begin their Premier League campaign away to Brighton on Sunday.
