Rainy Blue ~6 Gatsu no Ame~

The protagonist and his childhood friend, Ao, both aspired to become artists, but her life was tragically cut short by a car accident. While the protagonist was despairing from the loss of his friend, a small doll that Ao had once given him came to life. The doll, named Aoi, encourages him not to give up on his life and his dreams of art.

[summarized from Getchu and this review]