Kodama Trio by Gimpbeast. A kodama is a spirit from Japanese folklore, which is believed to live in certain trees (similar to the Dryad of Greek mythology). According to the 13th century Ryōbu Shinto manual Reikiki, kodama can be found in groups in the inner reaches of mountains. They occasionally speak, and can especially be heard when a person dies.
Please watch this anime. It will make you laugh, it will break your heart, and you will cry till there are literally no more tear, but please continue to watch it because the ending explains everything and it is satisfying. Remember, it will be confusing and sad and you will need to take a walk or do something but it is all worth it in the end. Never seen a more beautiful anime before! Please watch Clannad AND Clannad: After Story!