Mikey Anger is the quintessential millennial success story.

At age nine, the Keene native began making YouTube videos of himself engaged in one of his hobbies — customizing lacrosse sticks.

Three years later, the now 12-year-old has built his social media brand — Angry Bear Lacrosse — into a channel with more than 100 subscribers, an Instagram account with nearly 2,500 followers and a steady connection with multiple lacrosse equipment companies.

Not stopping there, he also used his growing brand to spearhead a fundraising effort within the local lacrosse community to raise money for veterans.

How has that part gone? As of last year, they had brought in over $10,000, according to Anger’s father.

“It’s really awesome to just think that, at the end of the day, all this stuff has really come together,” Anger said. “From just the love of a sport, to really just a company, to now supporting veterans in a way that has helped raise money for them. It’s been a huge journey, and it’s just going to keep on growing and keep on going.”

Starting out, Anger was your average youth athlete.

A big ball of energy on the lacrosse field, Anger is your average youth athlete. He loved playing midfield most, and his favorite position was face-off specialist, so he could attack the ball head-on and take control.

Turns out, that’s how he likes to approach a lot of things in life — head-on, in control.

He took an interest in going the extra mile with his equipment, personally stringing the heads of his lacrosse sticks and customizing them with special dyes.

“You see all these guys on YouTube like East Coast Dyes, like String King, all these different companies, they do videos of stringing and tutorials and stuff,” Anger said. “I’ve seen even kids online, around the age that I am now, like 13, 12, and they’re just doing all this stuff, and I was like, ‘Wow, that’s really what I want to do: be on lacrosse.

“It’s almost like in school, you go home, and you do homework; that’s what I kind of consider stringing as, kind of like a further education.”

One day he went to his father, Mike Anger, and said he wanted to start his own YouTube channel to review lacrosse equipment.

Mike balked at the idea initially. But Mikey was persistent, and his father eventually acquiesced — with conditions.

The account would be a joint one, shared between father and son, and Mike would supervise all interactions on Mikey’s posts.

Combining a play on Mikey’s last name with his favorite animal, Angry Bear Lacrosse was born.

Mikey was instantly comfortable in front of the camera, his father said, and the lacrosse community was very receptive to the videos, and to his posts on the Instagram account he made afterward.

Mike said in the three years since his son began posting online, he’s only had to block a couple comments.

Both say that working together on content for Angry Bear Lacrosse has been a great bonding experience.

“He’s come to me, ‘Hey Dad, can you help me edit this and get my point across,’ ” said Mike, who is also an assistant coach on Mikey’s Keene Crush youth lacrosse team. “It’s really transformed from him kind of taking the bull by the horns here to now kind of a partnership with him and I, which has been a lot of fun.”

The boy’s endeavor reached a new level once the equipment companies began to get involved.

In attacking, head-on mode, Mikey reached out to several lacrosse equipment companies, saying he’d like to review their equipment on his channel.

The companies responded favorably, and packages started showing up at the Angers’ door. Before long, he was an unofficial “Brand Influencer” for companies like Maverik Lacrosse, Signature Lacrosse, STX and Rocket Mesh Lacrosse.

“The lacrosse community, I would explain, (is) like no other,” Mikey said. “When we started, they were just so generous in donations. All these big-name companies instantly turned into like our friends and helped us out so much, and without their help, I think that none of this would’ve been possible.”

Mikey had developed into quite the entrepreneur. He wasn’t making a lot of money from Angry Bear Lacrosse, but he was making a few bucks here and there stringing stick heads for his youth teammates. And more importantly, he had developed connections with several people within the lacrosse community.

But there was another cause he wanted to pursue, something less profitable but bolder.

It was via a YouTube viewing that Mikey had come across Shootout for Soldiers, a non-profit organization that holds lacrosse events to raise money for charities benefitting U.S. veterans. One of the many events they hold across the country is “Shootout for Soldiers — Boston,” an annual event held over 24 hours in June at UMass Lowell, where a pair of veteran teams get to play, followed by teams that come to raise money for the cause.

As a passionate lacrosse fan and the son of a veteran — Mike Anger served in the Army National Guard — Mikey was made for this event, and he ran with it.

He needed to get a team together, so he went to Keene Crush Coach Chris Mercandetti and pitched the idea of their team taking part. Mercandetti had never heard of the event, but once Mikey explained it, he hopped on board, and others quickly followed.

“I’ve never seen anybody band together for any other charity like the lacrosse community has,” Mercandetti said. “To see Mikey get us all inspired here to do it, it’s been amazing.”

For one final touch, the Crush took on the team name “Angry Bears” for the event, donning red, white and blue jerseys, taking on as sponsors several of the equipment companies Mikey had worked. Mikey took the jersey number “1776” for an extra dose of patriotism and lead his team into the start of an annual tradition.

The Angry Bears will be playing in their third Shootout for Soldiers this June, and they’re no longer the only team from Keene taking part.

Last year, the Keene High girls’ lacrosse team — which features Mikey’s older sisters, Mia and Sammy Anger — joined the cause. Together, the two teams have raised more than $10,000 over the past two years.

This year, a third team has been added, calling itself “The Old Guard.” This team consists of some of the lacrosse players’ dads, as well as other older friends among Mikey’s social media supporters who wanted to take up their sticks and play.

“It’s gonna be essentially a men’s team versus the 13U boys,” said Mike Anger, who plans to play for The Old Guard. “I have a feeling they’re probably gonna whoop us, but it’ll be fun to get out there and be part of something fun and great and share that with the boys.”

To date, the three Angry Bear teams have raised more than $6,000 this year, according to the event’s website. Mikey leads the way with more than $1,200 in donations.

More contributions can be made at fundraise.shootoutforsoliders.com.

“When you’ve got a lot of great people around you, it really helps further your influence and confidence levels go up,” Mikey said. “When I have all these great people helping out and hopping on the team and kids that love to play lacrosse … it really goes from a one-person effort to a team effort. Team Angry Bear has gone a long way.”

According to Mercandetti, Shootout for Soldiers donates about 97 of the proceeds from the fundraisers to the charities, taking a small percent for overhead.

This year, the charity beneficiaries are Home Base Veteran and Family Care — a New England clinic that helps service members, veterans and family members heal from the invisible wounds of war: traumatic brain injury, post-traumatic stress and related conditions — and Operation Delta Dog — a group that rescues homeless dogs in Massachusetts and New Hampshire and trains them to be service dogs for veterans suffering from TBI and PTSD.

“Those two things are very deep in my heart,” Mike Anger said of Operation Delta Dog’s dual causes. “Having a working dog support one of our veterans is just a fantastic cause, so I’m very excited to support that, as well as Mikey is.”

In this new digital age, it’s easy to be cynical of the degrees of separation social media can create. But Angry Bear Lacrosse seems to be the perfect example of the medium’s original intent: bringing people together.

“Some people think of it as a bad influence, but I think of it as an opportunity to get what you have out there,” Mikey said. “That’s what’s really got all these people helping us, and on our team, to help Shootout for Soldiers and further other events and other lacrosse programs too.”