This is going entirely by how old they were when Free! was airing (from July 4th 2013), or in relation to each other.
-Just turned 17 in the story
-Born the same year as Haru, so younger
-Is a year younger than both Haru and Makoto
-Is 15, going on 16
-Same year as Nagisa
-Same year as Makoto and Haruka
-This post explains it all
-Once again, same as Makoto, Haruka, and Rin
-Same year as Nagisa and Rei
-Born 1 /4/1998
-Starting his first year of high school at 15
- Ai was the baby of the group until Momo showed up.
- You know Nagisa has played the age card on Rei.
- Haru is the oldest in general.
- Sosuke and Makoto are absolutely the mom and dad duo of the group, despite not being the oldest.
- In real time, they’re probably all in college by now (except maybe Momo).
- I still love these boys.
“Obviously one, I could hurt the team, especially in a game like that. And two, I could hurt myself. I just felt like it wasn’t worth it to go back out there and try to play.” -zach werenski on leaving game 3