KOUCHUU OUJA MUSHIKING: MORI NO TAMI NO DENSETSU

Based off of the game. Popo, and his family were harmoniously living with the insects in the forest until one day when his father left him and gave him a mysterious pendant with magical powers. Now, with mysterious events happened to his mother, he must travel with his newly found companions to the forest to solve the mysteries bound in the east. (Source: Anime News Network) — Description from AniList community (anilist.co).