Elise pays Well a visit to try and learn more about her fiance, but Well has been summoned away by the Royal Palace. There Well is given a mission from the king and together with Brantag and the palace magician, Armstrong, he quickly sets off to exterminate a dragon and other monsters. Elise joins in their campaign as part of the medical team.

Well is forced to participate in the kingdom`s martial arts tournament due to his nobility. However, he quickly gives up hope of winning when he learns that magic is prohibited in the tournament. Meanwhile Er, Iina, and Louise also decide to participate. While Er was taking it lightly at first, certain developments cause him to promise that he`ll win it.

Now that Well and the others are 15-year-old adults, they officially form their adventuring party, the Dragon Busters. However, before they have time to enjoy adventuring they receive a mandatory quest from the kingdom and venture deep into ancient underground ruins that no one has yet to return from alive. Well and the others are transported deep underground by a trap, and what awaits them there is...