Green Growth

Main character is a normal boy who gets invited by his friend on an adventure to the suburban forest. On his way there he gets separated from his friend and finds his a way to the mysterious fairy world. He becomes friends with many elves and animals there. However, elf village gets attacked by dwarves and monsters. Elves flee from the village, but protagonist can't leave his friends. His little battle begins today.

[From vndbreview]