The main character for the series.
The new leader of the special brigade Amaterasu which controls the Heart Hybrid Gear, and can use the ability "Heart Hybrid".
A straight-edged positive thinker who never forgets the kindness to take care of others. Surprisingly efficient.
17 years old, 2nd year in high school.

Member of Amaterasu and one of the heroines.
Uses the Heart Hybrid Gear Zeros, which specializes in melee combat.
Long silver hair, red eyes, white skin, thin yet big-chested.
Personality is stubborn and obstinate.

Member of Amaterasu and one of the heroines.
Uses the Heart Hybrid Gear Cross, a ranged attack type that has overwhelming attack power.
Long blonde hair with soft waves, blue eyes. Sexiest of them all.
Has a figure like American swimsuit models.
Very intelligent, and has high communication skills.

Member of Amaterasu and one of the heroines.
Uses the Heart Hybrid Gear Neros, which prides itself on having unparalleled strength in mid-range combat.
Long straight black hair.
Absolutely honest, obedient, faithful, and has a straightforward personality that never doubts what others say. Thinks that there is no true villain in this world. Has zero tolerance against lewd things...

Blonde ex-noble English girl. Small and flat-chested.
Admirable yet innocent. Thinks of Kizuna fondly.
An overseas student from England, she attends Ataraxia's middle school division.
On orders from Reiri, she looks after Kizuna.
At the same time, she is in charge of reporting to Reiri on whether or not Kizuna's relationship with the Amaterasu members is progressing.
She is good at cooking, laundry, and cleaning, giving her high specs as a female.
Her cooking repertoire is mainly English food.

Older sister of main character Kizuna.
Beautiful woman with long black hair. Highly intelligent and great athletic skills, a perfect human.
Commander of Ataraxia and the principal of the middle school and high school divisions. An overall great human.
Tough on others but is also tough on herself, and her being tough on others is out of looking out for them so that they don't lose their lives in battle.
She must recommend her little brother to perform lewd acts with female students for the sake of Heart Hybrid, so stress is secretly piling up inside her.