Is Shinda Ani no Shinyuu wo Hiroimashita coming back?

Taku Chiga (An Togashi), a first-year high school student living in Nasu Town, Tochigi Prefecture, one day happens to witness a young man, Mitsuru Morimoto (Mirai Fukahori), about to jump off a bridge and instinctively stops him. When Taku talks to Mitsuru after he regains his senses, it seems Mitsuru has nowhere to go and no money. Though suspicious, Taku couldn't bring himself to think Mitsuru was a bad person and reluctantly allowed him to stay for just one night. However, it later transpires that Mitsuru was the best friend of Suga's late elder brother, Harumi (Yoshida Haruto). Why has his brother's friend appeared now? What is his true identity? And what is the secret behind the sketchbook clutched in Mitsuru's hand—?