for everyone who's confused by the age difference not adding up, I read the raws and what seijiro (older dude) said was that ryou (high schooler) has a likeable way of doing things/demeanor that doesn't make him (sei) feel the difference of being a zodiac cycle (一回り hitomawari) apart in age and ryo got really close to him because of it. so sei didn't actually say that they're exactly twelve years apart in age, but kind of like there's at least 12 years between us
for everyone who's confused by the age difference not adding up, I read the raws and what seijiro (older dude) said was that ryou (high schooler) has a likeable way of doing things/demeanor that doesn't make him (sei) feel the difference of being a zodiac cycle (一回り hitomawari) apart in age and ryo got really close to him because of it. so sei didn't actually say that they're exactly twelve years apart in age, but kind of like there's at least 12 years between us