Isekai ni Teni shitara Yama no Naka datta. Handou de Tsuyosa yori mo Kaitekisa wo Erabimashita.

Synopsis

One summer day, Jin Konohana, a boy conscripted by his insolent sister to carry her belongings to a fireworks show, suddenly notices he is on a strange mountain. Alone in the mountains, Jin begins a life of survival. He wants to discard all troublesome things and live in peace and comfort. (Source: Earth Star Entertainment, translated)