Gaon Albums Chart
In December 2015, TTS released their third EP, a Christmas special album titled "Dear Santa". The album debuted at number 2 on South Korea's Gaon Albums Chart and has sold at least 60,456 copies to date. Seohyun wrote the lyrics to the title track "Dear Santa". As an effort to support music education for children in Asia, TTS contributed a part of the album's sales profits to a charity called "SMile for U", a campaign held between SM Entertainment and UNICEF.