The apprentice saint Emilia, who was expelled from the monastery, meets the all-powerful great witch Abigail. As she starts to enjoy delicious food and sleep well, her hidden "Divine Dragon-level" magical power explodes!! In front of Emilia and her companions, who have reached the deepest part of the Meririri Ancient Labyrinth, stands an incredibly huge door!! According to the guide Dia, it seems that Emilia must open the door by herself…!? Meanwhile, the supreme leader of the Tenka Church, Kanariera, calls upon Kokona, desperately trying to bring Emilia back…!? The more relaxed she becomes, the stronger she gets!? The heartwarming yet overwhelmingly powerful isekai life of the saint and the witch, Volume 4!!