Forrest is very polite and cordial with most people, even exhibiting some feminine traits. Despite his feminine appearance, Forrest has stated that he is not romantically attracted to men. Instead, his feminine appearance is due to a deep interest in fashion designing. Forrest has stated that the clothing he wears is of his own design. While he mainly focuses on designing dresses and other feminine clothing, he is perfectly capable of crafting masculine outfits, even creating a perfect hunting outfit for Kiragi in their support when he was taken on a hiking trip with him. He also is obsessed with cleanliness, refusing to dirty himself as much as possible, and adores cute animals such as rabbits.

Forrest's relationship with his father is soured originally due to Leo not approving of his son's interests. However, after Leo saw the error of his ways and became more accepting of his son's hobbies, their relationship improved significantly. Like the other sons of the royal princes, Forrest is destined one day to inherit Brynhildr. However, Forrest is not as eager as the others to inherit his weapon as he fears losing sight of himself when wielding the powerful tome. With reassurance from his father, Forrest believes that he will one day be worthy to inherit the tome, but not at the current point in time.