I believe they're making a reference to Yuubari City's terrifying regional mascot, Melon Kuma.
Just when I got back, Melon-chan came to Mugibase.How lovely... We've been waiting so long...Don't just sit around doing nothing kuma!Melon (and) BearYuubari and Admiral MugiWait a minute kuma!WELCOME YUUBARIKumaa★That's our Admiral!!!But this sloppy welcome banner...So pleased to meet youThis is what the Admiral spent all night preparing for...?The Admiral ('s inner self) is a Hokkaido native, isn't she...
The artist is a Hokkaido native.
