Agate is an antagonist in Roaring ❤ Hearts Pretty Cure. He is the eldest of the Void Triad, a trio of siblings who serve as Sardonyx's enforcers. Starting from episode 7, he adopts a disguise as Hisao Hoshikawa, a 21-year-old self-proclaimed freeter and frequent patron of Shooting Star in order to help his sisters keep tabs on Pretty Cure. He formally leaves the Void Clan in episode 17 and is reborn as a normal human man in episode 18.
Agate is a wiry and inhumanly pale young man. He has sharp features, and his eyes reflect very little light, giving them a glassy, inhuman appearance. His scruffy and bluish-gray hair grows out a bit above his shoulders and is pulled into a short ponytail. His outfit consists of a high-necked burnt orange tunic with burgundy trim, fastened at the center by a burgundy belt with a bronze buckle inset with a banded orange gemstone, and dark orange pants, which are tucked into shin-length burnt orange boots with burgundy trim. A flowing burgundy scarf, which sports snakeskin print, is tied around his neck, the back of his right hand is inset with a banded orange gemstone, and he has a burnt orange half-crescent earring in his right ear.
When disguised as Hisao Hoshikawa, he is slightly less pale - although still markedly so - and his eyes tint copper brown and become less inhuman-looking, albeit still noticeably dull. His hair tints bluish-black and becomes shorter, stopping below his ears. The gem on the back of his hand is not visible in this form.
During colder months, Agate's casual wear consists of a a red and burnt orange snakeskin print button-down shirt, dark brown skinny jeans, and dark brown lace-up boots. During warmer months, he wears a cream-colored, orange and red Hawaiian shirt, black pants, and black sneakers.
As a member of the Void Triad, Agate has been loaned a fraction of Sardonyx's gift, which he channels through his gem, allowing him to blacken the Roaring Sparks of targets and create Utsuroids. This power is not infinite and requires recharging for a period of time between uses, forcing him to switch off with his siblings. In order to aid with his given task, he is able to use magic to bind his targets in place, making it impossible for them to escape before their Roaring Spark is successfully extracted and corrupted, and teleport freely between Illuster and Earth.
Like his siblings, Agate possesses strength, speed, and durability on par with Pretty Cure. He is a strong and agile combatant, although he lacks Tourmaline's raw speed and Selenite's capability for potent short-range attacks. He possesses control over the power of earth, which he usually uses in the form of shockwaves channeled through his whip or directly from his hands. He also possesses a strong link with snakes; while he cannot directly control them, they recognize him as one of their own, instinctively flock to him, and can be convinced to carry out his wishes.
Due to his nature as a magical construct, he does not need to eat or sleep and is immune to illness.
- Agate's Whip: Agate's sidearm, a dark orange and black whip, which he primarily uses as a conduit for his powers, allowing him to create long-range shockwaves. However, he can also use it as a melee weapon, preferring to utilize it to bind his opponents or disarm them from afar.
Agate is a rock consisting primarily of chalcedony, alternating with microgranular quartz. Specifically, Agate derives his name from the variety known as snakeskin agate, due to its surface pattern.
Hisao means "long-lived man"
Hoshikawa means "star river"