The OVA will be pre-sold during the Comiket 87 starting on December 28, 2014, regular retail distribution of the limited edition package will start on January 30, 2015.

The episode bundled with the 13th volume is about the Sumo competition that held at Tempest for the first time, suggested by Rimuru. The three-part OVA bundled with the 14th, 15th, and 16th manga volumes is an original trilogy written by Fuse. Rimuru has been teaching Shizue's students at Ingracia Kingdom's Freedom Academy. The time has come for the school's annual outdoor training event, where the students will test their combat skills in the field. Rimuru is determined to win the competition and take home the prize money, but he is challenged by Jeff, an honorary teacher who sees Rimuru as a rival. The competition is underway when suddenly an unexpected enemy appears!

Mint is a girl who happens to be the princess of the world of dreams and magic. The natural environment of her world is a reflection of the dreams of the people on Earth. It is now in danger as people lose faith in their dreams and let darkness enter their hearts. The environment of Mint's world is starting to wither and die. On her 12th birthday, after a gala celebration with her father the King and her mother, she agrees to go to the world of humans to try to preserve people's hopes and dreams, and to prove that she has the qualities necessary to be a wise ruler. Her father arranges for her to stay with his sister, Mint's aunt Herb, who runs a gift shop on Earth called "Happiness Shop".

Ten thousand years ago, the immortal king Muyun was conspired by others for holding the Zhu Xiantu. After ten thousand years of sleep, his remnant soul awakened on the famous "Trash Muyun" of the Southern Cloud Empire of the Heavenly Fate continent.