Justin Bieber and Whitney Elementary school principal Sherrie Gahn on Wednesday's Ellen DeGeneres Show. (PHOTO: Screen Capture / YouTube / Warner Bros.)

Justin Bieber sure knows how to warm hearts.

In December, the 17-year-old superstar, along with camera crews from The Ellen DeGeneres Show, paid a visit to Whitney Elementary, an underprivileged school that has been profiled all season long on the daytime talk show.

School principal Sherrie Gahn and some of her students were on hand to great Bieber, who was presented with a blue school hoodie and given a tour of the school grounds.

On Wednesday, the same day the episode aired, Bieber took to Twitter to the promote the cause, for good reason.

@TheEllenShow working with u on things like this and #wetopia - just #makingachange. Thank you ELLEN. love u . . . #GIVEBACK . . . best part of the job, he wrote.

Bieber also gave a shout out to Principal Gahn.

trend it - #SherrieIsARealHERO, he added.

Bieber's day-long visit included a meet-and-greet with a 3rd grade classroom, a special concert for the school's 600 students, and a Q&A.

At one point, Bieber presented the school with a $100,000 check, along with an additional $100,000 worth of toys.

Thank you so much, this is the first time they're going to go home, and want to go home for the holiday, Principal Gahn told Bieber.

The Biebs is coming off a great 2011, thanks to his 3-D biopic, Never Say Never, his world tour and the release of his second studio album, Under the Mistletoe.

Bieber was also the most popular person on Google, as well as the most searched celebrity on Bing, according to annual reports from both search engine giants.

His third studio album, Believe, is one of the most anticipated music releases of the New Year. Kanye West and Drake have already been confirmed to guest star on the new album, due in the spring.

Scroll down to watch Justin Bieber visit Whitney Elementary. Have the tissues on standby.