[1] Inagaki studied microbiology and molecular genetics at Kyushu University, Japan, where he obtained his BS, MS, and PhD.
From 2005–2006, he was a guest scientist at the Max Planck Institute for Marine Microbiology in Bremen, Germany where he worked with Bo Barker Jørgensen.
[1] Inagaki was an editor of the book Earth and Life Processes Discovered from Subseafloor Environments: A Decade of Science Achieved by the Integrated Ocean Drilling Program (IODP).
He was the first to report the vertical and geographical distribution of microbes in deeply buried marine sediments of the Pacific Ocean Margins.
They set a world record for scientific drilling, reaching 2,466 meters below the seafloor off Shimokita Peninsula of Japan in the northwest Pacific Ocean.