Ace of Diamond is een Japanse animeserie van de zender TV Tokyo. De serie ging in première op 6 oktober 2013.
Een ontmoeting met catcher Kazuya Miyuki verandert het leven van de 15-jarige Eijun Sawamura. Hij neemt afscheid van al zijn vrienden en klopt op de deur van Seidou, een prestigieuze honkbalschool om zijn eigen kracht te testen. Daar ontmoet hij ook vele trotse honkballers. Een klassiek verhaal, maar toch nieuw en fris.
Kanemaru helps Sawamura get ready for the exams. Until Sawamura passes all his exams, he will be ineligible to play in a game. After a few practices, he manages to get a 30, two 35's, and a 36 on his test making him eligible for the tourney. As Chris watches Sawamura pitch into the net, he secretky thinks how he can fine tune Sawamura's grip into a great weapon that no one will be able to defeat. Furuya isn't as lucky and is forced to take the makeup test. Everyone receives their numbers. The opening ceremonies are held for the Tokyo Tournament. Only two schools, those whom make the championship game, will be able to go on to the National Tournament. After the Opening Ceremony, Seido returns to their practice facility. We see Furuya and Sawamura getting used to the fielding, but Kawakami appears to be struggling. Realizing it's time to boost Kawakami's confidence, the Coach takes him aside and announces he will be their ace closer and to not worry about having to start. Furuya is named the starter. Seido opens its first match against Maimon West, who is about to see what Furuya's fastball is all about.