Actually a collection of eight different stories. Each volume is its own story, centered around a girl named Tsubomi at the late end of elementary school, gradually experiencing various aspects of growing up and falling in love for the first time, while her life is changed by some manner of supernatural or sci-fi situation. Every volume is different, but each includes a great deal of discussion on ways girls' and boys' bodies change, the experience of first love, and the dangers of older predators. Includes astral projection, aliens, magic pens that bring drawings to life, more astral projection, time travel, body swapping, a girl haunted by a boy, and an android.
If you're a fan of puppy love, this will certainly be a fun read. Each volume is different, so whatever type of love story you want you should find something, whether you want one with a definitive ending or an uncertain one, love triangles or a single-target romance, strangers or childhood friends. Just be forewarned that, as a story that's strongly focused on growing up, you will inevitably also encounter a great deal of discussion of all aspects of puberty along with the love story.