I'm not sure specifically as I haven't read this light novel in detail. It could potentially be about a relationship, a personal journey, or some sort of emotional exploration. Maybe it's about a character who has been told not to die for someone, but that's just speculation.
You might try looking for it in specialized light novel stores, either physical ones if they exist in your area, or online stores that deal with Japanese light novels.
The answer to whether Kaori lives in the Kimi no Uso manga depends on how you interpret the story's progression and the author's intentions. It's a matter of in-depth analysis and understanding of the manga's narrative.
Haru does love Legosi in the manga. It's evident in the way she cares for him, shows concern, and their shared experiences strengthen their bond, making it clear that her emotions towards him are those of love.
Kimi ni Todoke's manga has a conclusive ending that isn't sudden or out of the blue. The narrative progresses smoothly towards its finale, leaving no major loose ends and providing closure for the readers.