The 23-year-old was signed for £1m, 24 hours before the closure of the transfer window, and arrives from Old Trafford with the bit between his teeth and an intent to impress at his new home.
"I'm really excited to be here and for me it's a fresh start and a new opportunity. I am at the point now where I wanted to be here on a permanent deal and I'm ready to give it everything," explained Keane to the Hull Daily Mail.
"It's a great set-up here and it feels like there's a really good atmosphere. I know the spirits are high in the group and I'm hoping I can come in and be a good addition to that."
Keane will be hoping he can face off on Saturday against brother Michael who plays for Burnley, having come out on top when the two last met. First he needs to acclimatise to his new surroundings after nine years at Old Trafford.
"I was at United a long time so it is a bit of an end of an era there for me," added Keane. "I felt like my opportunities there would be quite short now and I couldn't see a path through to getting game time and that's ultimately what I want, to play games and that's why I'm here."