"Kokoro"[2] is South Korean boy band SS501's debut Japanese maxi single.

[1] The group debuted in the Japanese market after only two years since their Korean debut to further spread their activities and challenge themselves outside of Korea.

[3] They released their Japanese single "Kokoro", alongside multiple versions, including one with all members and five featuring each member individually.

[5] It was also chosen as an ending theme song for an anime entitled Blue Dragon.

[6] NOTE: For the limited editions, "Alice" and its instrumental version are replaced by the solo song and its instrumental version of each member.