Diglett liked the singing of
DJ Leo's Dugtrio and wanted to join the group. It appeared at their concert in the Alola region and then later at the place they were staying at. It did an impromptu audition and Dugtrio liked its singing.
DJ Leo's Diglett is an Alolan Form. It wears a wig that was given to it by
Rotom Pokédex.
After Diglett joined the group, the group name became: "Dugtrio and Diglett with DJ Leo" or "Digdugleo" for short. It took the center position because
DJ Leo's Dugtrio all wanted the center spot.