Moving between worlds

Haru was an ordinary young man burdened by the harshness and loneliness of his childhood.
In a moment of despair, he lost consciousness to find himself awake in a completely different new world, where the sky had strange colors, and the people around him were mysterious. He felt confusion and disorientation, beginning to explore this new world where he discovered it embodied his memories and fears.
But what Haru did not know at first was that every time he visits this world, there is a specific mission he must accomplish within a set time. If he fails to complete the mission or misses the deadline, he would be trapped in this world forever, or worse — he would die. This mysterious rule added to his anxiety and made him desperately try to understand why he was here.