After thinking about what their quirks could be, it made me wonder the possibilities of them being pro heroes. You put your own ideas in the comments if you like.

Fuyumi A.K.A Beacon Hero: Emberfrost

Quirk:

"Firefly", She produces diamond-like crystals from her arms, a maximum of 40 at a time. Controlling their sizes, she can make them range from footballs to golfballs. Those crystals are able to hover through the air and glow a warm orange. Through training, Fuyumi able to mentally control the light intensity and movement of the crystals. Unlike the rest of the Todoroki family, she can't manipulate the temperature of her crystals, resembling diamond more then ice.

Fighting Style/Field Work:

She specialises as a rescue hero. She'd be able to light up dark areas, such as collapsed building or underground areas. Her fireflies can act as beacon for uninjured civilians, guiding them towards a safe location. She's also developed a code with her fireflies, so she use them to give distant messages.

By controlling the glow of her crystals, she can blind her opponent with flashes of light. If she's able to focus, she can cause distractions by making the fireflies glow in confusing patterns. Equally, Fuyumi can dim them to point they almost resembles normal ice - So a supermove she's developed is: Distracting an opponent with a bright firefly and then hitting them with a "invisible"/dim firefly.

With training, her crystals had increased to be the size of footballs. Like Hawks' feathers, the floating fireflies are capable of carrying full-grown men. In case of unexpected encounters with villains, Fuyumi has developed moderate combat skills. She propel her glowing crystals like canon balls, which can be deadly if hit, though they are quite slow moving. Also, she's able to cluster the fireflies together to make crystal barrier. Though B-Rank Villains or higher, usually have powerful enough quirks to shatter this barrier.

Public Reputation:

Her Hero ranking would be in the range of 180-200. While she has the high rescue statics, she's hindered by her lack of villain defeats. She's mainly boosted by her public approval rating. She has a genuine kindness lacking in celebrity focused heroes. She just wants to do her best and help people. Outside of missions she does charity work with civilians, seen as a good role model for this.

When it comes to combat, Fuyumi has underdog image in the public eye. A minority worries she's too naive as a hero and isn't tough enough on villains. Since she's self-aware of this issue, she specialises in rescue to minimize this issue. Regardless this doesn't bother her fans, who appreciate not all heros need to punch people and she fulfilled a specific niche.

She has a neutral opinion of the media and prefers a humbler life - She'll only do publicity if she believes its for a good cause. While she's tempted by the teaching profession, the only opinion is teaching at a Hero Course. Though she's too kind to make the high school students go through the tough training. (Also, from her personal experience with her father) Instead, she often visits schools to give speeches on Quirk safety.

Natsuo: Choose not to have an official name, but media dubbed him as "Mist".

Quirk:

He breathes the various forms of water vapour from his mouth. He can control the temperature of the vapour to change it's form: boiling steam, fog or frosty mist. He can then mentally effect the vapour once it's in the air.

Fighting Style/Field Work:

He'd be a support hero for both villain combat and recuse, needing to be apart of a team to most useful. He can control the temperature of an area by covering it with his vapour. Most ideally, he can cool down a fire. Natsuo can give himself and his team greater stealth over villains by hiding themselves in his fog.

For villains, he struggles to directly engage with them in hand-to-hand combat. His quirk, since it's gas, offers little when it comes to physical attacks. At best, he can fire a weak projectile made from condensed vapour. The most damage it can do is moderate bruising to the normal human skin. He can use this same condensed vapour as armor, enclosing his punches and kicks in it, to give them extra power. To overcome this weakness, he uses support items in the form of weaponry. For close range, he has knife training while for long-ranged he has throwing weights like Sir Nighteye's.

Instead, he prefers to use mind-tricking and long distant tactics. Using his vapour's smoke form, he can disorient opponents. Another example is he'll make make silhouettes in the fog. Hopefully this will trick the villain into panicking and waring themselves out. Though, he usually replies on a physically powerful ally to actually to land the knock out.

Public Reputation:

Hero Ranking 220-240. He's opposite of Fuyumi, while he's well-rounded in all social contribution stats, he has a low public approval rating. Like Eraserhead, Natsuo is anonymous from the public. Due to his father, he sees the hero rankings as a corrupter, so he promised himself to not care about his ranking.

Though keeping his public anonymity is proving to be increasingly difficult. Since Natsuo is a support hero and a social guy, he's been apart of the same hero team for years. While Natsuo allows his teammates to take credit in the media, as his group's popularity rises, people naturally become curious about their most mysterious member.

As the public are unaware of Natsuo's childhood - They're mainly confused by him and consider him wasted potential. He has a laid-back and goofball personality that could make a likeable hero - So why does he hide himself? In One instant, a journalist critiqued Natsuo for "ignoring a hero's duty to be a role model". In that rare case, Natsuo allowed his hidden frustration to slip, snapping for the journalist to leave him alone.