Jun Shirasaki’s love life takes a wild turn when he finds himself caught between the Jinguji twins—his childhood friends who are as different as night and day. Rumi, the older sister, pairs a boyish charm with a maiden’s heart, while Naori combines girlish looks with her deep love for otaku culture. As feelings grow and confusion mounts, Jun must navigate this unexpected love triangle next door. 

(Source: Crunchyroll)

Jun Shirasaki and the Jinguji sisters are neighbors and childhood friends. 
When the older sister Ryumi, who was Jun's first-time girlfriend, broke up with him, she will say something that will make the three people's relationship, their first loves, and their romance to become slightly complicated—?
 
(Source: ComicWalker, translated)

We can't always just be childhood friends. A first-love comedy with a pair of twins!
 
(Source: Kadokawa, translated)

Reira Asano