translator here! congrats, you're the first one to notice this! but their age gap really starts to matter less as the story progresses, bc it doesn't end at those ages... it's a spoiler, but you can take a quick guess on what i'm referring to here
should also mention that kanta just started college himself too. so ryo's a high school first year (15, turns 16 in ch 4. birthday july 6) and kanta's a college freshman (18-19, birthday oct 29). it is a four-ish year gap, feels more three years if you take the jp school year in account...but i gotta do more thinking on that bit. the story starts in april 2021 according to kanta's phone in ch 2
Hes in college and he just started high school?