Celtic have announced the signings of South Korean duo Hyunjun Yang and Hyeonkkyu Kwon on five-year deals.
Attacker Yang joins from Gangwon FC for a fee of around £2m while Kwon moves from Busan I-Park for £1m.
Forward Mario Tilio has arrived from Melbourne City, Odin Thiago Holm has been secured from Valerenga, while Celtic have made fellow midfielder Tomoki Iwata a permanent signing after his loan from Yokohama F Marinos.
Yang, who was the K League young player of the year last season, played in all but one of Gangwon’s 22 league games this season.
Defensive midfielder Kwon’s last game for Busan was in K-League 2 against Seongnam.
Celtic manager Brendan Rodgers said: “We’re looking forward to both players joining up with the squad and playing their part in what we hope will be another successful campaign.
“Yang a player that we’ve looked at closely and who we think will further enhance our attacking options which, of course, already include his fellow countryman Oh.
“He’s an exciting player who was the young player of the year in South Korea last season, which is an indication of his quality, and I’m sure he’ll be looking forward to having a big impact at the club.
“It’s also clear that he was very keen to make this move to Celtic so I know he’ll be delighted that everything has now been agreed and we’re really looking forward to working with him.
“Again, Kwon is a player that the club has been aware of for some time, so it’s great that we’ve completed the deal and I know that the player is delighted with the move.”
Yang said: “I’m very pleased to come to Celtic and I’m looking forward to meeting my new team-mates and to begin training with them.
“This is a move that I wanted to make and so it is great to be here in Scotland now as a Celtic player.
“I have spoken to Hyeongyu Oh who has already told me great things about the club and its supporters, so I can’t wait to meet them and play in front of them.”
Speaking after his move, Kwon said: “This is a great move for me, to be joining the Scottish champions, and I am looking forward to working with the manager and the players.
“I know that Celtic is already very well-known back home, and I am sure the support will continue to increase now there are three South Korean players, and it will be good to play alongside them.”