[1] Mizoguchi made his first appearance for Kashima Antlers Youth (U-18) aged 16 in the Japan Club Youth U-18 Football Championship, making four appearances en route to the semi-final of the competition before being knocked out by Sagan Tosu U-18s.
[2] The youth team reached the semi-final of the same competition in 2021, with Mizoguchi playing six games throughout.
[3] In July 2021 it was announced that Mizoguchi would be joining the first-team squad of Kashima Antlers for the 2022 season.
[4] He made his debut on 18 May 2022, coming on as an 83rd minute substitute for Koki Anzai in a 3–1 J.League Cup victory against Gamba Osaka.
[5] In June 2022, he made the starting XI for the first time in a 2–1 Emperor's Cup win against Niigata University HWSC.