He looks very similar to a Mii from the other Wii Series games, called Saburo. They have the same eyebrows and eyebrow colour, the same eye colour, the same skin colour, and the same hairstyle and hair colour and the same favourite colour.
This does not suggest a relation, as no Mii from the Wii has a confirmed relationship.
Ross' official face image, extracted from Wii Music
Ross'official full body image, extracted from Wii Music