きみとユリイカ (Series) favorite_border

[DeepL Translation - needs review] Introduction of the first volume: A boy named Watari suddenly arrives at the home of Mai, a high school girl living alone. Mai and Watari, a boy genius returning from Scandinavia but with a somewhat mysterious and fast-paced personality, end up living together!　Their cute and warm life together is about to begin!

(Translator: DeepL)