Love Is Indivisible by Twins

Koi wa Futago de Warikirenai, written by Shinon Takamura, follows a boy named Jun as he falls in love with the twin girls who are his childhood friends and live next door; both of which who couldn’t be more different from each other. Rumi, the older sister, who has a boyish exterior but a maiden-like personality while Naori is super girly and also a super otaku. (Source: Crunchyroll)