TORONTO — This is a story about two Canadian things with a well-documented history of ups and downs, and their white-hot bromance.

The pop star Justin Bieber and the Toronto Maple Leafs have had a little thing going on for some time, dating to nearly two decades ago when Bieber was a boy. It was also the last time the Leafs were reliably winning a playoff round or two.

For the past few years, Toronto hockey fans have been in on it, seeing Bieber at home games sitting in a suite or behind the Leafs bench with his father, Jeremy. He has become good friends with the Leafs stars Auston Matthews and Mitch Marner in particular, friendships that really took off around 2019.

So if the whole world didn’t know by now that the Leafs make Justin very happy, this should make it abundantly clear: On Wednesday he released a music video for his song “Hold On” and called it a “love letter” to the team.

The Leafs had lost the previous night, 4-3, to the Winnipeg Jets, so like any good Boyfriend, Bieber dropped the song when they needed a pick-me-up.

“It’s cool,” the goalie Frederik Andersen said this week. “Auston’s relationship with him is pretty tight, so it’s fun to have a musical talent like him be a big fan of us, and I think likewise a lot of us appreciate his music.”

The song is the fourth single from Bieber’s coming album “Justice,” which is set to be released March 19.

This is not the rapper Lil Wayne, who is from New Orleans but front-running for the Green Bay Packers in song. Bieber has been obsessed with the Leafs since he was a kid, with the twin-size bedsheets and wallpaper to prove it.

For those paying attention, the evidence has long been in plain sight. Bieber’s wife, the model and influencer Hailey Baldwin Bieber, rocking a Leafs hat in New York. Bieber with Carlton, the Leafs mascot. Bieber beside himself over a playoff comeback last season. Then there was the time when, he proclaimed 2021 the year the Leafs would win the Stanley Cup.

“Biebs is a very special person and an incredibly talented artist,” the defenseman Morgan Rielly said this week. “He’s eager to work with the team and spend time around the guys. I think that’s a pretty cool opportunity. We’re very fortunate to play for this organization, and I guess that’s just one of those things that kind of comes with it.”

In December 2019, Bieber invited Matthews, Marner and Tyson Barrie, now with Edmonton, to his hometown, Stratford, Ontario, to play pickup hockey with his childhood friends. Matthews wears clothes from Drew House, Bieber’s fashion line. Bieber and Matthews did an Instagram Live when hockey was shut down in the early days of the pandemic. Bieber has taught Marner the Yummy dance. Going back a decade, Bieber dropped in on a Leafs practice when in Toronto for a concert.

In late February Bieber got in touch with the team and asked them to make a video set to “Hold On.”

“It was Justin’s idea; he wrote a love song and the Maple Leafs are one of the great loves of his life,” said Shannon Hosford, chief marketing officer for Maple Leaf Sports and Entertainment. “He reached out to see if we’d be interested in helping him release the song. From our perspective it was exciting to have a fan reach out to do something with us. He’s a hometown fan and his connection with us is authentic.”

And his influence is enormous, far more than the team and league combined. Bieber has 166.5 million Instagram followers, 114 million on Twitter, and another 61.5 million on YouTube. By comparison, the N.H.L. has 6.3 million followers on Twitter and 4.5 million on Instagram, and the Maple Leafs about a third of that.

“We saw it as an opportunity to reach a new fan base, and take hockey outside of North America,” Hosford said. “They wanted to represent the team as much as possible. It’s less about the game and more about the personalities of the players. His association makes this go beyond our die-hard fan base. You understand there’s a love for the sport but it doesn’t really go beyond North America.”

Hosford said the team saw an immediate bump across its social channels and platforms from the video, mostly younger people outside of the Toronto market.

“You can’t plan this out, and you couldn’t imagine the impact,” Hosford said. “You could never pay for it.”

Hosford confirmed that the arrangement was not a formal one. No money was involved. It was simply a case of Bieber saying to the Leafs, Let Me Love You. And the Leafs saying yes.

“It’s something that came from a fan,” Hosford said. “A fan that just happened to be Justin Bieber.”

The Maple Leafs have 13 championships, but have not won one since 1967, the longest stretch without a title in the N.H.L. On top of the standings as of Friday with 19 wins and 7 losses, they had lost three straight but were back to winning on Thursday, accompanied by a soundtrack and a public display of affection.