You're my sun

After the death of her sister, Natsuki decides to adopt her nephew Kenji and take care of him as a single mother. On the other hand, Yosuke is a kind and lonely young man who has lived a hard childhood and who over time has cut ties with all his relatives. By chance, these two lost souls end up meeting and together they will take care of Kenji as if they were his real parents. However, just when life seemed to smile at them, Natsuki dies in a traffic accident. A few years later, Kenji, who has already turned twenty, meets Yosuke while visiting the grave of his mother. What will have happened between them? And, what is more important, will they be able to solve the problems of the past to move towards a new future?