Though 10-year-old Frank Rosiles is no longer here, his best friend thinks about him often.

Frank and Trevon Alfred met in kindergarten and spent most of their time together -- in and out of class -- until fourth grade. "He was my No. 1 best friend," Trevon said, recalling their walks to the park together, the toy cars they traded and how Frank would cheer him up by asking him silly questions when he was feeling down.

All he has of his friend now is the Superman toy figure Frank once gifted him and a photograph he keeps next to his bed.

"Every single day I wake up, I look at the photo and I just think of when he was still with us," Trevon told CNN. "And that's how I get through my day."

Frank Rosiles -- called "Frankie" by his loved ones -- was killed by a stray bullet during a drive-by shooting while he was playing with his cousins in his uncle's home on February 5, the Yuba County District Attorney's Office said. The bullet bounced off the home's front door and a ping-pong table before striking Frankie in the abdomen, the office said. Within 40 minutes, he was pronounced dead.

He is among more than 1,300 children and teens who have been killed by a firearm so far in 2023, according to the Gun Violence Archive. Firearms became the No. 1 killer of children and teens in America in 2020, surpassing motor vehicle accidents, which had long been the leading cause of death among America's youth, federal data shows.

The day after his death, Frankie had planned to go shopping with his mom, hoping to get all his classmates small presents for Valentine's Day. Instead, Lori Rosiles went alone.

She delivered the presents to his class herself, and the students' group hugs offered some small comfort during the first days after her son's killing.

But months on, it feels like nothing will fill the gaping hole Frankie's loss left in her life -- and in the lives of his three older siblings, who have been grappling with grief, trauma and depression, Rosiles said.

"I feel empty, there's nothing inside of me," Rosiles told CNN. "Everybody's world just keeps going and keeps going and here I am just standing there because on February 5, my world stopped."

He loved baseball and Bruce Springsteen

October 4 would have been Frankie's 11th birthday.

To those who knew him, his presence was like sunshine: He was always smiling, eager to help, quick to crack jokes to cheer others up, easy to get along with and, sometimes, you'd catch him singing to the latest tune stuck in his head.

He was an "old soul in a little kid's body," his mom said. He had the music taste to prove it. In the car, Frankie would play songs that usually spanned the 1960s through the '80s. "I'm Goin' Down," by Bruce Springsteen, was "one of our songs," Rosiles said.

And he was so smart, his mother said.

"He wanted to learn; he wanted to do well; he was very competitive with himself," said Tiffany Bautista, who taught Frankie last school year. He was a part of a "combo" class with fifth graders that only a handful of younger students had been selected to be a part of. "He would always try to be the first one done because he wanted to go around and help other kids, and I think that was like a drive for him."

Frankie loved science and math and had won awards for his academic achievements as well as for his behavior in class. When Bautista created an after-school STEM program, Frankie signed up to be a part of it. By that time, he had already developed a strong interest in coding and robotics, she said.

He also had a business mind, helping run successful lemonade stands in his neighborhood and selling his mom's cookies to neighbors when the family was struggling financially.

And he had many dreams for the coming years: He wanted to go to a large anime convention, to visit Japan and, later, he wanted to be a scientist, maybe an astronaut.

"The potential person that he would have been -- and the loss of that -- is not something that any of us who knew him will recover from," Bautista said. "He would have been good at whatever he chose because he was really a passionate kid and very driven."

When he wasn't at school, he was most likely at the baseball field just steps from his family's apartment, playing with his brother and friends. During Little League season, he was #7. To honor him, the league named a baseball field "Frankie's Field of Dreams."

"This young man has touched a LOT of our hearts," Olivehurst Linda Little League members wrote on Facebook the day after Frank died. "He will be missed tremendously."

Family members also set up a verified GoFundMe to support Rosiles and her children.

Read other profiles of children who've died from gunfire

'I feel like he picked me himself'

Frankie loved many things: God, his family, his friends, making TikTok videos, learning small facts every day, dancing to Chubby Checker's "The Twist" and anime.

Most of all, he loved his mom.

"He never left my side," Rosiles said. "He loved me so much, I feel like he picked me himself: Like God was like, 'Who do you want to be your mom down there?' and he was like, 'Oh there, I want that one.'"

He always waited for his mom to come home from work before he went to sleep.

"I would walk in and I would always hear, 'Hi mom!'" she said. "So happy and cheery and full of life."

At the top of her bed now, Rosiles has set up a "Frankie wall," filled with pictures of him and his siblings, a dream catcher he owned and a poster from "Demon Slayer," his favorite anime.

Shortly before his death, Rosiles bought Frankie a costume of his favorite character from the show, Tanjiro -- a teenage hero who, after losing his family, enlists in a demon-fighting army to save the world. "He wore that costume almost every single day," Rosiles said.

She decided to bury him in it.

Before his death, Frankie shared with his mom that he planned to take part in a writing competition at school. He drew a cover picture, titled the story "Dragon Slaying," and asked Rosiles if she thought he had a chance at winning. But he never got a chance to write his story.

If he had, "he would have won that contest," Rosiles said.

"I know he would have."