Nike Lemercier (ニケ・ルメルシエ Nike Rumerushie) is the main protagonist, the fourth and youngest princess of the Rain Duchy and the Empress of the Sun Kingdom.
She has the power to call forth the rain when she sings and is noted as being one of the most powerful rain summoners to date.
Nike has long, wavy copper hair that ends just below her shoulders and green eyes. She is also notably busty.
Optimistic, stubborn and caring, Nike quickly gains the people's affection as well Livius’, who clearly loves her. She is even more popular than Livius among the people in the Sun Kingdom as she seems to interact with them on a regular basis and helps them out whenever she can. She can make friends easily due to her easy-going and amicable nature.
Nike was the fourth and youngest princess of the Rain Duchy and was considered to be the best and most talented of the rain summoners.
As a child, Nike was unable to summon the rain and was sent to live with her grandmother and cousin Kitora, who was also unable to summon.
Though Kitora would give up, believing that he would never be able to summon rain, Nike would persist and eventually becomes the Rain Kingdom's best singer. Though later on in the manga she loses her power to summon the rain.
Later on, just before the start of the story, The Sun King, Livius I, demanded one of the Rain Duchy princesses in exchange for the Duchy's continued autonomy.
Nike was chosen after having lost a game of rock-paper-scissors to her elder sisters and was sent to the Sun Kingdom.
Despite her first impression of Livius and the conflicts between them, Nike gradually comes to love and care for the young Sun King.
At first meeting, Nike regarded Livius as a 'brat' and observed his blue eyes as 'non-child like'. She was later thrown in prison by the Sun King and managed to escape, only to come back and snuck into his room when Neil had already exited. The two always argues for the most minor reasons although it is revealed that Livius and Nike shared an intense bond to one another, so much so that the Sun King would not give her up to her own family, and that he is willing to risk his life just to have her as his partner, and in the manga he ventured outside the walls of the kingdom to save Nike from poison. There are also parts where Nike hurt herself just to get to him. Still Nike commonly shows her affection to him when he is not aware, a primary example is when he is sleeping.
Bardouin is the half-uncle of Livius. He and Nike did not have a very pleasant meeting, for Livius evidently seemed to be jealous as the older man constantly flirted with Nike. Nike, being herself, saw through the facade he was putting on when they were alone in the bedroom. She said in a firm voice that he did not love her and it was all fake, which Bard whole-heartedly agreed with, and claimed that he would have fallen for her somehow due to her interesting personality, and that it was a test of loyalty. The half-uncle wanted to know if Livius' wife was actually suiting to him and wouldn't betray him. Later, he was thrown into prison by Livius thinking that Bard had somehow attracted his future wife, which Nike desperately declined. Soon the king and Bard became friends again with the help of Nike's rain, and he was assigned to the position of prime minister again.
Luna is Livius' childhood friend. She is completely head-over-heels for him, and had many attempts to dispose and humiliate Nike, of which she took hard. It is not confirmed that Nike was jealous throughout the whole episode/chapter but her actions seem to be of that. Luna, in a scene, had danced with Livius after another try in humiliating her in front of everyone and possibly due to the compliments of the guests towards Luna and the sayings that they should be together and not Nike, this lead to the rain princess slipping away. Luna quickly follows and says harsh things towards her while Neil eavesdropped. After everything, Nike is comforted by Livius by saying that he would not let her go no matter what the others say and they share a quiet dance together. Luna spied on them. The next morning Nike is challenged by Luna and the ocean kingdom princess manages to get into an accident regarding Nike's sayings of how she loved Livius, and was saved by Nike. They become closer and Luna finally accepts that Nike is Livius' soulmate. In the manga the princess returns for help.
Neil is the butler of Livius. He is the practice partner of Nike in dancing and is mostly the one to tutor her in some subjects. Neil often scolds Nike of being improper toward Livius or just being genuinely improper, they are in good terms nonetheless. He is often interrupted by Livius throughout these scolds, with the young king reminding him that he is used to it.
- Nike is noted to be strong enough to beat up four palace guards, although she was thrown in prison for it. 
- Though Nike's rain manipulation works through her singing, she whispers when she uses the wind.
- ↑ Chapter 001