Natsu Hinomoto is a 13-year-old second-year junior high school student and a central character in the story. She has auburn hair tied into a side ponytail with a yellow bow and bright yellow eyes. Natsu is a childhood friend and classmate of Minamo Sorano, and the two share a very close bond, often understanding each other without the need for words. Her nickname is Natchi.

Natsu dreams of becoming an idol and actively works toward that goal at Alicepia, a secret wonderland where young girls can visit and pursue their hobbies. She is naturally gifted in songwriting and composing music, talents she uses to support her own ambitions and those of her friends. Her personality is cheerful, energetic, and determined; she always gives her best effort, even when facing dangerous enemies or difficult situations. Natsu's optimism and perseverance make her a reliable and encouraging presence.

In the story, Natsu plays a key role in the awakening of Minamo's powers as a princess. During a monster attack at a concert, Natsu encounters a Jammerwock, and the incident triggers Minamo's transformation into Princess Ripple. Throughout the series, Natsu continues to support Minamo and the other princesses, using her musical abilities and steadfast friendship to help protect Alicepia. Her role is that of a supportive tritagonist rather than a direct combatant, but her creative contributions and emotional strength are vital to the group's success.

Natsu's development centers on her pursuit of her idol dream while learning to balance her personal goals with the larger conflict. Her relationship with Minamo is the emotional core of her character; she is not only Minamo's best friend but also her confidant and motivator. Natsu also interacts warmly with other princesses and Alicepia's inhabitants, showing her sociable and caring nature. Her notable abilities include composing music and writing lyrics, which she channels into performances that inspire and empower those around her.