Recently can't get my mind off this song composed by Matsumoto Ryoki (松本良喜), did a search and found a lot of different version!!!
I prefer the 徳永英明 (Hideaki Tokunaga) version, how about you?
Japanese(中岛美嘉) Original Version - sung by Nakashima Mika
Japanese (徳永英明)Version - sung by Hideaki Tokunaga
对不起，我爱你 (Korean Version) - sung by 朴孝信
对不起，我爱你 (China Version) - sung by 1983 group
对不起，我爱你 (Singapore Version) - sung by 蔡淳佳