Despite being a famous celebrity, Nelson is a rather timid boy, even to the point of being afraid of things such as spiders, as opposed to his brave and heroic TV show counterpart. In the dub, he describes himself as "...just a middle schooler from the suburbs". Nelson often feels very lonely because he always to keep his public image as the "Sparrow" and can never be himself with people. Although usually mild-mannered, Nelson display some degree of boldness as he quickly approached Yuma Tsukumo and whisk him away without the boy's consent, though his rather intimidated by his mother.[1]

Nelson speaks using the boyish pronoun "boku", but when acting as "Sparrow" he used the more masculine pronoun "ore" and speaks in a deeper voice.[1] Sometime after his Duel with Yuma, he solely refer to himself using "boku", showing he's being more himself.[2]

Fuya's Offer

Nelson offers his cards to Yuma.

Nelson is very fond of Yuma, since Yuma is the first person to tell him to be himself. When Nelson first met Yuma, he opened up to Yuma about his loneliness and even directly asked Yuma to be his friend. Even under the "Numbers" influence, Nelson tells Yuma to stay away from him when he was causing havoc around Heartland City for Yuma's own safety.[1] After their Duel, Nelson continues to admire Yuma for his never-give-up "kattobingu" spirit and was happy to see him when they met again. Nelson perceptively notices Yuma's talent to make people happy through Dueling, as Nelson was one of them, and he encourages Yuma continue to make people smile through Dueling.[2] When Yuma getting ready for his Duel Astral, Nelson was the first among Yuma's friends to try to lend Yuma his cards.[3]

According to Astral and Yuma, Nelson has changed since their last Duel, being bolder and more himself since breaking free from his mother's pressure, and said that his style of Dueling has change too. During the World Duel Carnival, Nelson shows to be quite flashy when acting as the "Star Sparrow" around his fans, but maintains his polite and modest nature.[2]