女の子を天国に連れていくには

Yuichi is dead. Such a kind boy, jumping off a railway bridge? It shouldn't be possible. "I'm sorry, I couldn't do anything, even though I knew Yuichi was going to die." "Huh?" "Because I can see it." Chizuru, a girl in high school and Yuichi's classmate, says this, revealing that she "knew" about Yuichi's end. Yuichi's best friend, Mitsufumi, who is left behind, begins to unravel the mystery of his friend's death together with this mysterious girl. —And the two of them know about another "ending" - that Chizuru will die in a year. (Source: Manga One, translated)