|Season 1, Episode 71|
|Air date||March 1, 2015|
The Final Lesson
September Sky (9-gatsu no Sora no Shita, ９月の空の下) is episode 71 of the Diamond no Ace Anime series. The episode follow the storyline from the second half of chapter 220 to chapter 223 of the manga.
At the Fall Tournament block games, Furuya wears the ace number and shine in both pitching and batting. Sawamura is finally allowed to practice in the bullpen but still struggles to pitch to the inside. Chris arrives to help.
Kuramochi express his concern about Sawamura to Miyuki and becomes angry when Miyuki says that its the team that is the priority and not the individuals. Miyuki however, admits that it's partly his fault why Sawamura fell apart and the team can't afford to lose him because of the yips.
At practice, Kataoka tells Sawamura to join the batting and fielding practice. He assigns him to the outfield and Sawamura complies. Haruichi think Sawamura is not his usual self, but thinks Sawamura has come to terms with the situation he's in. Haruichi however is mistaken when Sawamura gets annoyed after Kataoka assigns Furuya to pitch at practice.
In Seidou's first official match for the fall, Furuya wears the ace number and shine in both pitching and batting. Sawamura is seen cheering from the dugout with the number 18. At school, a group of students muse as to why Sawamura is included in the roster when he's doing so poorly at practice. Sawamura hears this and gets annoyed. Meanwhile, the retired third years talk about the Group selection for the Fall Tournament. Isashiki admits he want to hit balls.
On a rainy day, Sawamura runs around the field and wonders what Kataoka want from him, by including him in the roster. Furuya runs past him wanting for everyone to acknowledge him as a "true" ace. Sawamura, not wanting Furuya to run ahead of him, starts sprinting to catch up turning their warm up into sprints, tiring both of them . Kawakami reminds them to pace themselves for practice has just begun. Sawamura is told to practice in the bullpen. He is then instructed to throw to the inside with Kataoka at-bat, while someone records his pitching. Sawamura struggles and Ochiai could only wonder why Kataoka care so much about Sawamura.
Miyuki later advises Sawamura not to think so much since he doesn't have good control anyway. Ochiai asks Kataoka how high is he aiming for this Fall Tournament. He express his concern about the team but wants to give Furuya more experience for his growth to become the ace that Seidou needs, by giving up on the Fall Tournament. Ochiai thinks that raising Furuya as the ace is the fastest way to win nationals next year. Kataoka disagrees saying that he won't sacrifice the welfare of the team just for Furuya.
Sawamura continues to practice alone after Maezono and Haruichi leave. Sawamura reflects on the words from Miyuki, knowing that he is right. Chris arrives and Sawamura is happy to see him.