Question: Which artists recorded both "Love Letter" and "Face?"

Context paragraphs:
Happy Pledis 2nd Album: Happy Pledis 2nd Album is a charity single by the South Korean music label Pledis Entertainment's artists Son Dam-bi, Kahi, After School, NU'EST's JR and Baekho, Hello Venus's Yoo Ara and Lime and Pre-School Girl Park Jung-hyun.  The album was released under the name "Happy Pledis 2nd Album" and is a charity release.  As NU'EST and Hello Venus hadn't officially debuted then, the album doesn't include all the members of the two groups, and NU'EST went by the name "Pledis Boys".  The album consisted of tracks "Love Letter", "Winter’s Tale", and "How Are You".

Money Honey (Bay City Rollers song): "Money Honey" is the title of a 1975 international hit single by the Bay City Rollers, taken from their album "Rock n' Roll Love Letter".  The power-pop recording was issued in the US as the album's lead single in January 1976, reaching number nine on the Hot 100 in "Billboard" magazine that March.  "Money Honey" was the Bay City Rollers' second US Top 10 hit.  It reached number seven on the "Cash Box" chart.  The follow-up single was the album's title track, "Rock and Roll Love Letter" (US #28).  In the UK, "Money Honey" was released in November 1975 and reached number three.

Girlfriend (The Pillows song): "Girlfriend" (ガールフレンド , Gārufurendo ) is the fourth single by The Pillows.  It was released as an 8cm CD on March 24, 1995.  The B-side track, "Girlfriend (Love Letter Version)", which was an arrangement of the A-side title track, was used in the award winning 1995 romance movie, Love Letter.

Love Letter (Gackt album): Love Letter is the fifth full-length studio album originally released by Japanese solo artist Gackt on February 14, 2005 in Japan.  A Korean language edition, titled "Love Letter - For Korean Dears", was released on June 16 of the same year.  It continues the unplugged theme of the earlier compilation album "" but consists of new material, save for the song "Dears", originally from his album "Mars", and "Etude", originally from the demo tape by his indie band Cains:Feel.

NU'EST: NU'EST (Hangul: 뉴이스트 ; acronym for New Establish Style Tempo) is a South Korean boy group formed by Pledis Entertainment in 2012.  The group debuted on March 15, 2012, with their digital single "Face".  The group consists of JR, Aron, Baekho, Minhyun, and Ren.  They have released two studio albums, one Korean and one Japanese, as well as five EPs.

Love Letter (Ai Otsuka album): Love Letter (stylised as LOVE LETTER) is the fifth studio album released by Ai Otsuka on 17 December 2008.  It come in a CD-only format and CD + DVD format.  Thirteen songs are included; four from her singles Pocket, Rocket Sneaker / One × Time (both songs as it is a double A-side single) and Kurage, Nagareboshi.

Love Letter (R. Kelly album): Love Letter is the tenth studio album by American R&B recording artist R. Kelly; it was released on December 14, 2010, by Jive Records.  It was written and produced entirely by Kelly.  A departure from his previous work's contemporary sound and sexually explicit themes, "Love Letter" incorporates classic soul music influences and features chivalrous lyrics concerning love and forgiveness.

Love Letter Tour: Love Letter Tour was a summer tour headlined by R&B artist R. Kelly.  It supported the album, "Love Letter".

Triangle (band): Triangle (トライアングル , Toraianguru ) was a Japanese pop group that formed and debuted in the late 1970s.  They released their first single, Triangle Love Letter in mid 1978 and their last single, Koi wa Tekkiri Ba-Bi-Bu-Be-Bo in 1980.  The group only released two albums, Triangle Love Letter and Sanjūsō / Triangle 2 in 1978 and 1979 respectively.  Sony Music Entertainment released Triangle Single Collection in 2008.

Love Letter (Berry Good song): "Love Letter" is the first single album by South Korean girl group Berry Good.  It was released on May 22, 2014, one day after the music video for title track "Love Letter", which is a remake of the song released by Click-B in 2000.

Supporting paragraphs: Happy Pledis 2nd Album NU'EST
Answer: NU'EST