After 15 years in the K-pop industry, TVXQ! is still finding new accomplishments to land.

The legendary Korean outfit makes their debut on Billboard's Social 50 chart this week, starting at No. 29 as the week's only new entry. For the week of Dec. 21 to 27, TVXQ! saw a slew of activity on Twitter, earning 4,000 new Twitter followers (up 411 percent from last week), 16,000 Twitter mentions (up 64 percent) and 173,000 Twitter reactions (up 922 percent). The group also saw a surge in Wikipedia activity, earning 5,000 Wikipedia views (up 23 percent).

The Social 50 is powered by data tracked by music analytics company Next Big Sound and ranks the most popular artists on Facebook, Twitter, Instagram, YouTube, Wikipedia and Tumblr. The chart's methodology blends weekly additions of friends/fans/followers along with artist page views and engagement. The chart’s latest tracking week ended Dec. 27 and sees the first four slots occupied by K-pop acts including TVXQ!'s labelmates EXO and NCT (at Nos. 2 and 3, respectively).

Not only did TVXQ! release their latest LP New Chapter #2 : The Truth of Love, which was billed as a 15th anniversary special album and included a collaboration with Taeyong of Social 50 mainstay NCT, members Max and U-Know also celebrated their anniversary with a career-spanning performance on Korean television. On the year-end 2018 MBC Music Festival special, the guys delivered one of their signature hits in 2008's "Mirotic" as well as 2018's "The Chance of Love," their comeback single after serving the country's mandatory military service which became their biggest domestic chart hit since 2014.

As a fun K-pop history fact, TVXQ! made their first public appearance as a group -- at the time, a quintet -- on Dec. 26, 2003 at a Korean concert for Britney Spears and BoA before releasing their debut single "Hug" the following month. (Another fun, unrelated, fact is that Spears co-wrote the song "Look Who's Talking" that would end up on BoA's self-titled English album released in 2009.)

Watch TVXQ! show why they remain K-pop royalty in the MBC Music Festival performance below: