D-kun

From Kokorodatabase

Daisuke (more affectionately known as D-kun) is the Shirogane family's pet dog. He's more or less an NPC.

Shirogane Ryou has a history of losing track of the canine, which actually resulted in his meeting one of his childhood friends, Roy Bancroft.

The mutt absolutely adores food, particularly plain glazed doughnuts since they are high in sugar, and let's face it, taste really good. While the dog's a bottomless pit, he's managed to avoid becoming overweight in some way or another, probably by running off the extra calories; he loves to go on walks and the like. D-kun knows a few tricks as well, which include the usual sit, stay, heel, roll over, play dead, beg, shake routine, but he'll also fetch sticks or try (and fail) to communicate things to people. He's fairly smart, just easily distracted...

D-kun's got a lot of energy, even though he is technically no longer a puppy. In fact, D-kun should be getting rather old and weathered, but he hasn't, which doesn't quite add up. This may be because D-kun is a summon. He has the ability to sense monsters in the area and is highly protective of his family, but the whole theory itself hasn't been proven (aka the idea was halfway retconned).

When Roy visited Ryou in Japan and attempted to give the dog back to him (the dog had escaped the fire by chance), the blond said there was no way it could be the same animal, though later realized it was. It was also D-kun who found Shirogane Jishou after he had been revived.