Okoru to Shinimasu.

The protagonist Nanami Nao is quite the contrarian. His childhood friend Aoi Miki, always upset at his meddling, has been inflicted with a mysterious disease!? To save her, "love" is necessary...? As the two of them become (temporary) lovers, in the end can the protagonist manage to save the heroine, his childhood friend!? [Translated from Freem!]