If you're looking for manga similar to Sequence, you might like these titles.
A 16-year-old high school girl, Michiru Isshiki, has cool childhood friends--- her next door neighbors, Ryouhei and Shuusuke Kuwa. Shuusuke, the same age as Michiru, is a pure-hearted, passionate rugby player. On the other hand, Ryouhei, three years their senior, works as a model, and is the campus crush. Because Michiru is a pure-hearted person, Michiru opposes the playboy Ryouhei, but she realized her true feelings when she saw a kissing scene between Ryouhei and his girlfriend, Youko!
It's summer vacation time, and no one is more excited about it than 2nd year high school student Karin-chan. Her childhood friend Sakumi-senpai is coming home from college to visit! Karin and Sakumi, along with his younger brother Tatsumi are childhood friends. Sakumi hasn't been gone long, but now that he is back, Karin can really see a difference in him. Just seeing him makes Karin's heart beats faster. Her crush on him hasn't changed.
Hikaru, Ryuuhei and Miyabi's houses are close to each other. So they have been best friends since childhood. They think their relaitonship won't change. But over time, little by little, different feelings developed.
A love triangle story about a girl who can't decide between her brother and her childhood friend.
Hiyoko, Ibuki, and Chihiro have been friends since childhood, growing up together as close as siblings. But when they entered high school, that relationship began to change. Chihiro confides in Ibuki about his long-standing crush on Hiyoko. But Hiyoko herself has feelings for Ibuki. What will happen to their relationship?
Anzu currently works part-time at a beach house however when it comes to serving male customers, she can't help but be cold and shy. When she accidentally spills a drink on one of them, a male co-worker saves her who ends up being her childhood friend Rei. Anzu is happy to reconnect with Rei, however, Rei might be after a bit more...?
As a child, Mao spent all her time at Hiro’s house across the street. Going to his house always made her feel cheerful. A few years later, Mao’s father gets remarried and Mao finds herself with nowhere to call home. Hiro ends up letting her stay with him in the house he's been occupying alone since the death of his parents. A love story unfolds, between two childhood friends of different ages.
Hazumu is a shy and quiet boy who loves flowers and is forced to rely on his tomboy childhood friend Tomari as a bodyguard. Yasuna is the prettiest girl in school but she avoids men like the plague… until she meets Hazumu. Encouraged, he confesses his love; heartbroken, he heads for the mountains to be with his flowers. As if Hazumu’s troubles aren’t enough, his day is further ruined when an alien ship accidentally kills him. Luckily, alien technology exists that can revive him, but not without a price: Hazumu returns from the dead, but in the form of… a cute girl?!