Key of Heart / Dotch (2006) "Winter Love" (2006) Alternative Cover "Key of Heart" is BoA's 20th Japanese single and 6th Korean single. The single was available solely in CD+DVD format in Japan with a "special summer low price" and first pressing to commemorate this for being her 20th single.. Learn how releasing your heart-wall can result in freeing your heart from unnecessary emotional baggage. Established as the largest and most innovative care and education provider for children and young people in the UK and Ireland, the Keys Group incorporates several.