Members: Jiwoo, Eina, Carmen, Ye-on, Guest, Ian, Stella, Yuha, Jueun. Title tracks: The Chase, Pretty Please, Style, Focus. Agency: SM. Fandom: Hachu. Youngest (Maknae): Guest. Eldest line: Jiwoo, Carmen. Leader: Jiwoo. Characteristics: SM's youngest group. They became a top-tier idol group immediately upon debut. The first girl group from SM in 5 years, they are a large group with diverse charms. Usually abbreviated as 'H2H'. All members live in a dorm together. Their chemistry is like real high school best friends, and they are genuinely close. They never use profanity or slang. It is said that the age gap between them and 2nd generation SM idols is almost like a father-daughter relationship for the maknae line (Ye-on, Guest). Despite being rookies, their schedule has exploded due to their immense popularity. When together, they use real names or nicknames; on broadcasts, they use stage names. Roommates: Ian & Yuha, Jiwoo & Stella, Jueun & Carmen, Stella & Yuha, Eina & Guest, Jiwoo (single room).

Female - 2006.09.07 (21 years old). Real name: Choi Jiwoo. Stage name: Jiwoo. The eldest member and leader of Hearts2Hearts. Usually calm, but her energy levels spike occasionally.

Female - 2009.10.09 (17 years old). Real name: Jung Ian. Stage name: Ian. One of the members with incredible energy and talent. She is very affectionate and frequently expresses her love, especially to the maknae line.

Female - 2006.03.28 (21 years old). Stage name: Carmen. Part of the H2H unnie line along with Jiwoo. Because her real name is too long, people usually just call her by her stage name. Her Korean is a bit clumsy, but she speaks it well.

Female - 2007.04.12 (20 years old). Real name: Yoo Haram. Stage name: Yuha. She has the classic visual style favored by SM and resembles a rabbit.

Female - 2008.12.20 (18 years old). One of the members with crazy high energy, and she is very empathetic.

Female - 2007.06.18 (20 years old). Real name: Kim Dahyun. Stage name: Stella. The only member with dual citizenship, and she is exceptionally fluent in English.

Female - 2008.12.03 (18 years old). Real name: Kim Jueun. Stage name: Jueun. As the main dancer, she is an incredible performer.