A romcom centered around two childhood friends: Tarou and Umi.
It took four tries professing his love, but he finally gets a 'Yes'.
Not long after, Tarou finds that Umi only has 100 days to live!

Short manga from Migihara's Twitter.
Volume 1: The Lonely Spirit of the Spring
Volume 2: Angel
Volume 3: Assorted stories

(Source: MangaDex)