It is I, as well as my best friend, TrainMastR. He's a great friend, he's brought my spirits up when I've had a hard time, and I'm grateful to him for that. Like me with "Do your best!", he also has a sort of catchphrase: "I like trains!", which is where he got part of his name, TrainMastR. (He really does like trains.)
TrainMastR is a Kind Warrior in Miitopia, he likes helping others. He's of the Cancer, the Crab, his birthday's in the first half of July.