The Hibiscus Keychain is what Lucia got as a replacement birthday present from Kaito, when her real birthday present, a pink surfboard with a Hibiscus on it, burned down in a fire. It is seen in episode 13 in Mermaid Melody Pichi Pichi Pitch and episode 28 in Mermaid Melody Pichi Pichi Pitch Pure.
Kaito gives the keychain to Lucia at the end of Episode 13.It represents the real pink surfboard that Kaito was originally planning to give to Lucia for her birthday, however, it got burned down by a fire involuntarily caused by Eriru, making Kaito give Lucia the smaller keychain surfboard after her birthday.It is unknown where Lucia had kept the keychain afterwards,but obviously she wouldn’t have thrown it away.
The keychain is shown again in Episode 80 when Lucia holds the keychain in front of her to admire it.
The keychain is a pink surfboard that that has a Hibiscus flower on it. The Hibiscus flower on the keych is rathered detail and is red in colour. There’s a sliver chain attached to the end of the keychain.