We meet the Gekomon in Season 1, Episode 25.  Gekomon love good music. They were overjoyed when DemiDevimon told them about a young girl named Mimi with a voice sweet enough that it just might wake their leader, ShogunGekomon, who had been fast asleep for a long time. 

The Gekomon found Mimi and dubbed her "Princess Mimi".  She loved the attention!  She loved it so much that she kept making excuses to avoid singing the song.

Tai and the others finally showed up and woke ShogunGekomon (only to wish they hadn't... )

Mimi ran into a single Gekomon later in the series and recruited him to help fight the Dark Masters.