What is the connection between Amagi Brilliant Park and Full Metal Panic?
It seems that the author liked Bonta-kun's design so much, so he reused (with Shiki Douji's appoval) it in this series. 

From a summary of the afterword of LN Vol. 1:


  As for the secondary main character "Mofuru", I ended up borrowing Bonta-kun of FMP. I just couldn't separate the two characters in my head, so I had the idea of just using Bonta-kun directly. I thank Shiki Douji for giving his approval.