You Are My Only Evergreen

Seika Uno joined an integrated secondary school as a high schooler and felt alienated in the new environment, until one day when she met a young man in a mansion she wandered into by accident. With help from the mysterious young man and touched by his guitar, Seika's world begins to expand.

A suspenseful platonic love story begins between two people connected by music!

(Source: Kadokawa, translated)

Note: Includes 19 main chapters originally serialized in 22 parts and 25 extra chapters.