|Birthday Date||February 14|
|Home Place||Akamaru Town|
|Alter Ego||Cure Heartbeat|
|Season||Melodia Pretty Cure!|
Furukawa Koi (古川 コイ Furukawa Koi) is one of the main Cures in Melodia Pretty Cure! and is the leader of the team but doesn't have the theme colour of pink. Her alter ego is Cure Heartbeat (キュア ハートビート Kyua Hātobīto) and her theme colour is blue. She may look cute on the outside, but Koi is very shy and tends to keep her head in a book or hands on a keyboard writing stories of her own. But along with her reading nature, she is very good at fighting and has a strong sense of justice and has excellent fighting skills.
Her catchphrase is "My heart will not stop beating!" (私の心暴行を停止されません！ Watashi no kokoro bōkō o teishi sa remasen!), while her sad catchphrase is "My heart has wilted..." (私の心はしおれた... Watashi no kokoro wa shioreta...).
Koi has blonde hair that reaches her shoulders and has purple eyes.
As Cure Heartbeat, Koi's hair is blonde with a blue and black hat sitting on top, and her eyes are still purple.