They habitually write their name as H?L, replacing the Latin "A" with the Greek "?" or Lambda.
Hal went from music arrangers into a music band and then back to music arrangers, arranging songs for many Japanese artists. Toshiharu Umezaki (sometimes written as Toshiyasu Umezaki) is known as the main member and leader of the band, which had gone through some deformations in their structure.
The sound of Hal is mainly a lively digital beat at the edge where the electric guitars are used a lot, as a special feature and typic in their arrangements.
Hal started out as music arrangers in 1999, and became known especially for the work that they did (and are still doing) with Ayumi Hamasaki. "Appears", "Fly high", "M", "Evolution" and "No way to say" are some of their most famous tunes with her. They also have worked with some other artists like Ami Suzuki, the KinKi Kids, Every Little Thing, and Dream.
In 2000 the group of men did a casting to choose a female vocalist for forming the musical group Hal, which was an idea of Toshiharu Umesaki and Atsushi Sato's. Finally the singer Halna was chosen to be a part of Hal and they signed a deal with record label Avex Trax. They temporarily stopped their group as arrangers after the work with "Grip!" from Every Little Thing.
After the release of seven singles and two studio albums as Hal, the band got separated in 2003 because Halna decided to leave the group and get away from the spotlight, with the release of their final album, called "Singles", a compilation album with all the singles released by the band, and they started to work again as arrangers with Ayumi Hamasaki and Tackey & Tsubasa. Atsushi Sato also left the band that year to arrange music on his own, under the nickname of ats-. He has recently worked with Ami Suzuki under Avex, and Yuta Nakano, who left the band in early 2001 is currently working as remixer and also arranger.
Currently Umezaki and Shimizu keep their name Hal active, arranging songs for Japanese singers and music groups.
From Wikipedia
