Kakuta cut short his loan with Vitesse last week.
"Two months before the break, I spoke with Gael. He regretted not starting, but saw that the team worked fine. He thought about it and decided to leave," said Boez.
"He said: 'It is now the fifth time I've been loaned, it's time for me to join a club on a contract where I could fight for a starting spot'. We agreed.
"It is unfortunate, in January, but this is what happened. It's a shame because Gael was important with his speed."