Newcastle United have completed the signing of striker Yoshinori Muto after he was awarded a work permit.
The Magpies had to wait for the relevant documents to be ratified in order to complete the deal, despite Muto having already agreed a four-year contract.
The club confirmed on Wednesday that the process has been completed, meaning he becomes their fifth signing of the transfer window, following Martin Dubravka, Ki Sung-yueng and Fabian Schar and the loan deal for Kenedy.
However, the 26-year-old will have to miss Saturday's friendly with Augsburg while he waits to be granted a visa.
"As the first Japanese Newcastle United player, I am honoured to be a player for such a big club," said Muto, who joins from Mainz for a reported £9.5million fee.
"I hope to achieve good results – that is what I am here to do. I would like to perform well and leave my name in Newcastle's history."
Newcastle boss Rafael Benitez added: "I am really pleased to have Yoshinori Muto with us. We were following him for quite a while.
"Hopefully, he can bring us his energy and work rate and help the team to improve and be better for the new season."
The news is a boost for Benitez, who admitted after Wednesday's 4-0 friendly loss to Braga that he is "really worried" about Newcastle's hopes for the season.
"When things are not going well off the pitch you can see a reflection on the pitch," said the Spaniard, who admitted "everything" behind the scenes gave him cause for concern.
"The fans have to be concerned, we are concerned. I'm really worried."
