Dragon Collection

Dragon Collection (ドラゴンコレクション, Doragon Korekushon) is a Japanese social network game created by Konami that was released on the GREE social networking platform in 2010. A manga adaptation titled Dragon Collection: Ryū o Suberu Mono was serialized from 2011 to 2012 in Kodansha's shōnen manga magazine Weekly Shōnen Magazine. It was collected in six tankōbon volumes. A trading card arcade game was released in 2013. An anime television series adaptation began airing on April 7, 2014, alongside Monster Retsuden Oreca Battle, another Konami video game adaptation.

Plot
Through an unexpected turn of events, an ordinary elementary school student, Hiro Enryu, finds himself in the world of the "Dragon Collection" game. This is a world called Dragon Earth, where gods, humans, and monsters exist side by side. Those who roam this world using a magic book, called a Grimoire, and cards to summon monsters and search for treasures that bear the powers of dragons are called Dracolle Battlers. Despite his bewilderment, Hiro becomes a Dracolle Battler and, together with the friends he meets there, begins his adventure to become a legendary "Dragon Master!”