Ace of Diamond (Japanese: ダイヤのAエース, Hepburn: Daiya no Ēsu) is a Japanese baseball-themed manga series written and illustrated by Yuji Terajima. It was serialized in Kodansha‘s shōnen manga magazine Weekly Shōnen Magazine from May 2006 to January 2015. A sequel titled Ace of Diamond Act II started in August 2015.

An anime television series adaptation ran from October 2013 to March 2016. An anime adaptation of Ace of Diamond Act II aired from April 2019 to March 2020.

In 2008, Ace of Diamond received the Shogakukan Manga Awards for the shōnen category. In 2010, it won the Kodansha Manga Award for best shōnen manga.

Plot

The series follows Eijun Sawamura, a baseball pitcher with an unusual pitching style that naturally causes the ball to move unpredictably at the plate. Sawamura plans to go with his friends to a local high school and play baseball to the best of their abilities. However, one scout from the prestigious Seido High School approaches him and offers him a scholarship and a chance to make it to the nationals. Sawamura decides to pay a visit to the school, and it changes his entire outlook on the future. Seido and their main rivals attempt to help the upperclassmen make it to nationals during the summer tournament. Once the summer tournament ends, the upperclassmen will be forced to retire, but Sawamura will help them to success, despite his lack of control.

Some time later, Sawamura and his teammates, Furuya Satoru, Kominato Haruichi and Miyuki Kazuya, lead a new team, along with a few returning faces, through the fall tournament. Their overly ambitious goal is to go to nationals during the fall tournament and convince coach Kataoka that he does not have to resign.

Ace of Diamond Act II continues to follow Sawamura and the team as they prepare to compete for the summer tournament. With a new year, new faces appear and join the Seido baseball club. Sawamura and Furuya compete with national level teams, being able to identify their own strengths and weaknesses and further mature their pitching style, all the while they are competing with each other to earn the coveted ace title. Simultaneously, the Seido batters are improving themselves to become as fearsome as the batting talent of their previous year’s first-string team. With all of these preparations, Seido is aiming to win the summer tournament before the upperclassman have to graduate.

Ace of Diamond
Cover of the first tankōbon volume, featuring Eijun Sawamura
ダイヤのAエース (Daiya no Ēsu)
Genre	Sports
Manga
Written by	Yuji Terajima
Published by	Kodansha
English publisher	NA Kodansha USA
Imprint	Shōnen Magazine Comics
Magazine	Weekly Shōnen Magazine
Demographic	Shōnen
Original run	15 May 2006 – 14 January 2015
Volumes	47 (List of volumes)
Anime television series
Directed by	Mitsuyuki Masuhara
Written by	Kenji Konuta
Music by	Frying-Pan
Studio	Madhouse Production I.G
Licensed by	PH Creative Programs Inc.
Original network	TXN (TV Tokyo)
English network	PH Yey!
Original run	3 October 2013 – 28 March 2016
Episodes	126 + 5 OVA (List of episodes)
Manga
Ace of Diamond Act II
Written by	Yuji Terajima
Published by	Kodansha
Imprint	Shōnen Magazine Comics
Magazine	Weekly Shōnen Magazine
Demographic	Shōnen
Original run	19 August 2015 – present
Volumes	30 (List of volumes)
Anime television series
Ace of Diamond Act II
Directed by	Mitsuyuki Masuhara
Written by	Kenji Konuta
Music by	Hajime Hyakkoku
Studio	Madhouse
Licensed by	Crunchyroll (Worldwide excluding Asia)
Original network	TXN (TV Tokyo)
Original run	2 April 2019 – 31 March 2020
Episodes	52 (List of episodes)
Manga
Cat of Diamond
Written by	Yuki Okada
Published by	Kodansha
Magazine	Magazine Pocket
Demographic	Shōnen
Original run	12 January 2022 – present