Sanagi

"Let's look at it together someday..." A vague memory of a promise made to the girl he had his first love with in his childhood to look at the chrysalis of the leucanthemum butterfly, which was said to be very beautiful. Hideaki, who had been living like an outcast, confined himself to a dimly lit, dilapidated room after falling ill and never going outside, began to dream of that past time again and again. One day, Hideaki picks up a strange, rainbow-colored butterfly chrysalis from a child making noise outside, and notices that it is getting bigger and bigger...

(Source: Hakusensha, translated)