Soleil has a cheerful and energetic personality. Though she is not too shy, she can get anxious about her surroundings. Soleil is very popular with girls due to her cool personality and likes to hit on them. Because of her cool personality, she can tend to be immensely shameless, as she does not mind changing clothes, even if there are other people watching. In her B Support with Ophelia, Soleil does not panic when Ophelia casts a spell to exchange bodies.

Laslow states that Soleil has "good taste" in both men and women. In the english localized version of the game Soleil's support conversations and personality suggest that she prefers females instead. In most of her supports with the other male children, if they reach an S rank support, they simply become better friends rather than marrying. The only exceptions to this are Forrest and the male Avatar. In the Japanese original version however, while Soleil still has a weakness towards some females, it is much more ambiguous which one she prefers, and her S rank supports have her normally marry the other male children.

However, she isn't completely without embarrassment; in her B-support with Dwyer she tries to practice dancing in secret, only for him to misinterpret it as a demon-summoning ritual, but Soleil threatens to blackmail him into keeping quiet and helping her learn. Also, her supports with the male Avatar have him try to help her to not sweat or faint around girls because she thinks that it's getting in her way of being a warrior by practicing blindfolded (under the effects of a potion in the Japanese version) and pretending that the Avatar is a girl.

She adores her father and loves being protected by him, yet she did not inherit his dancing skills; stating that she has no sense of rhythm. Growing up alone in the Deeprealms caused Soleil to become very protective of Laslow, stating that she always was unsure when he would be seen again. She thinks that her mother is very cute, so she feels jealous of her father for marrying her mother. Unfortunately, this makes her a mild annoyance to her mother as she annoys them in their supports as they try to work by excessively complimenting her in flirtatious ways.