In the 2008-2009 pantomime season, Kai appeared in Dick Whittington. He played Dick to John Challis' (Only Fools and Horses) King Rat.
At the wrap party for the first series (season) of Torchwood, Kai broke some ribs after a fall.
Kai appeared in his first pantomime in the 2007-2008 season. He played Prince Charming in Snow White.
Kai is an associate actor at the Theatr Clwyd.
Kai is scared of coachroaches.
Kai's earliest memory is of Manchester United winning the FA Cup in 1983. He has remained a fan of the football (soccer) club since then.
Kai first met Eve Myles who plays his wife in Torchwood many years ago when he went to see her in a production she was doing in Mold (North Wales) with a friend of hers. After the play, they had dinner together and then went to a fete where they had their faces painted as clowns.
In school, Kai was part of the senior football (soccer) team; he was the goalkeeper.
In 2005, Kai played the role of Ronnie Williams in the stage play The Life of Ryan... and Ronnie. The play is based on the life of famous Welsh comic duo Ryan Davies and Ronnie Williams.
In series 1 of Torchwood, Kai appeared nude but seen only from the back getting out of bed and slapping his backside to the tune "A Shave and a Haircut" in one episode. He also appeared nude, but with objects hiding him from the front in the episode Out of Time.
Kai's father is named Mark and he's a GMB union official; Kai's mother is named Yvonne and she's a cleaner at the British Legion Club.
Kai: (On why he thinks "Torchwood" is very popular in the US) I think they are enjoying the Britishness of it, even the Welshness of it, because Cardiff looks fantastic and there is just nothing like it being made in this country.
Kai: (About what makes him happy) Family, friends, food and football. Oh, and Wales, obviously!
Kai: (Answering a question about if he believes in the supernatural) I do, yeah, I've never seen a ghost, but I have had a few weird things happen to me. Once, I was in a house and I felt the temperature drop suddenly, then I heard something go bang, bang, bang, on the floor above. There was definitely nobody up there. So I ran to the pub!
Kai: (Commenting on the team in charge of Special Effects on "Torchwood" and his being shot for the episode "Meat") The bullet hit was brilliant; I was stunned how it worked. Really, really brilliant. I've been shot before, but never this graphic, this special effects' way. The guys are brilliant, fantastic!
Kai: (On the atmosphere on the set of Torchwood) It's unbelievable, the energy and the spirit on the set is phenomenal, led superbly by John and Eve.
Kai: (About having to leave his hometown Llanrwst to have a career) If I could do what I do here in London and still live in Llanrwst I'd be very happy.
Kai: (On how much Eve Myles and him can bring to a scene in Torchwood) Eve always brings quite a lot to the table, she's always got plenty of suggestions, and myself and Eve always have lots of ideas before the scene starts. Because it can get a little bit monotonous, Gwen and Rhys having arguments. So there are scenes where it possibly could have been an argument that we've turned into quite playful, lighthearted arguments - that sort of suggestion.