Responses
Also if he actually got raped they maybe should've made it more apparent...
I think he's on the final year of middle school when he met the uke 6 years ago so (final year middle school -14yrs old) ( 14+6 =20) so yeah he's 20 years old by then.
It's not well explained but there's a 5-6 year age difference. So if the seme is 20 currently, sei is 14. Back then, if sei was in fourth grade, sugiara was in 9th grade.
I can't figure out their age difference. Sei is "about 20," and black-hair was in middle school (so ~ age 12) 6 years ago. Which would mean 2-3 year difference. But the photo seems to have a little larger disparity, and neither of them seems to be in high school or college... Sei's job also doesn't seem to be entry-level, so maybe he's 21-ish?