HALCALI is a female hip-hop group consisting of two members known by their stage names Halca and Yucali, which are variants of their actual names, Haruka and Yukari. Halca was born on April 21, 1988 and Yucali was born on July 18, 1987. They both grew up in Meguro, Tokyo, and became friends while attending the same dance school while they were in grade school.

In 2002, Oshare Track Factory (RYO-Z and DJ FUMIYA of hip-hop group RIP SLYME) was looking for a new project to produce. They held a "female rapper audition," and Halca and Yucali won. This was the birth of the unit.

On July 26 of that year, RIP SLYME held a free concert at the Nippon Budokan. During the performance, RIP SLYME called the two girls onto the stage from their seats, and HALCALI gave their first performance of their debut single "Tandem" in front of approximately 10,000 spectators.

"Tandem" was released in January of the following year, peaking at #19 on the singles charts. HALCALI released their second single ("Electric Sensei") in April, and it fared slightly better, reaching #16. They finally broke into the top ten in July with their third single, "Girigiri Surf Rider."

In between "Electric Sensei" and "Girigiri Surf Rider," HALCALI made their first TV appearance, but not in Japan. They were featured on the British network BBC during a segment about hip-hop in Japan.

During the summer of 2003 (while they were on break from school), HALCALI completed their first tour, holding free concerts in several cities.

"HALCALI BACON," the duo's first album, was released in September 2003. It peaked at #5 on the album charts, becoming the first album by a female rap artist to break the top ten. The album remained on the charts for a total of 20 weeks.

HALCALI continues to release new albums and singles, some of which have been used as theme songs for anime series. They have also been active in other areas. In July 2005, they became the regular Wednesday MCs on the Tokyo FM radio program "BUZZ ROOM." Yucali has regularly appeared on the TV music show "Shin Domoto Kyodai" since October 2005, and Halca served as an MC on "MTV Apt." between April and June 2006. Both girls have also often appeared as models in fashion magazines.