Li Gado is a microscopic organism and specialized hyperdoctor whose job is hunting down dangerous pathogens. He's equipped with a flea-like exosuit that protects him from the atmosphere and operates a small round robot as his primary tool.
He showed up in Hellsalem's Lot tracking the pathogenic terrorist Gemnemo, determined to capture him. Things went sideways immediately when the weapon Li Gado had built for the job got totaled after smashing into Leo's head. Rather than give up, Li Gado followed Leo home to construct a replacement, using the encounter as a chance to warn him about the Gemnemo threat and how serious the situation actually was. Leo didn't take it very seriously at first.
After salvaging usable parts from the destroyed weapon, Li Gado managed to build a new one. Since his own equipment was in the shop for repairs, he needed backup—and he'd noticed Leo had some real talent guiding Sonic with his eyes. That was enough to convince him Leo was worth recruiting for the job.
Content compiled by AnimeList.moe from publicly available sources.
