Akanesasu Sekai de Kimi to Utau

Akanesasu Sekai de Kimi to Utau (茜さすセカイでキミと詠う) or Reciting With You in the Glowing Red World is a Japanese smartphone app game produced by GCREST.

One day, after passing through a torii, you came to a dangerous world called Hinomoto.

In Hinomoto, the sun doesn't rise anymore and the sky is always the depressing red color.