Youta, a young man living in solitude, attempts a summoning spell out of loneliness, hoping to simply converse with someone. Despite being warned of his lack of summoning skills, Youta manages to summon Mumu, a dragon trapped in darkness for centuries. Initially terrifying, Mumu reveals a desire for companionship, much like Youta. As they bond, Youta realizes Mumu's emotional nature and clinginess. To navigate their friendship, Youta seeks to manage the whims and needs of his eccentric dragon companion.