Hana*Hana made their debut in 2000 after an indies career and appeared at the same year's NHK Kouhaku Utagassen due to the success of their second single. However, the sudden suspension of their career three years later led to speculation over them being on bad terms. The duo revealed that on one day after they had a meeting with their staff about their concert tour, they were called to go to their agency's office where they were told the news. Apparently, their agency then was a company in the business of making soft toys for crane games but that didn't turn out well so it had to withdraw from the music business. As a result, the copyright issues were not clearly settled and there were songs which they could not receive any royalty income for.
However, when the duo reflected on what happened then, they said that it wasn't that bad as it seemed because they could have done the same thing at some point of their career. Back then, they were so busy with various activities such as appearing on TV that they had no time to create new songs. As such, when they made a comeback in 2009, they were thankful that they could stand on their own feet and deliver music which they are confident about. If not for the period when they took a break, they might not have made it this far anyway.
Sources: Yomiuchi Hochi / Sponichi