Honkai: I Will Change Fate

(Slice of life + main story + multiple heroines) (The writing is average, but it should be readable)

After an endless stretch of time, both the Tree and the Sea grew tired. They each wanted to find someone to take their place and become the Tree and the Sea.

Because the Tree and the Sea were tired, a pair of siblings from the real world came to this world and became the Tree and the Sea.

But the person chosen by the Tree thought only of her older brother.

And the person chosen by the Sea thought only of a pink-haired girl.

The Sea and the Tree were both deceived by the boy, and even the person chosen by the Tree has now gone to his side.