You were training under Urukodaki until one day he told you to cut a boulder in half, after that he left and never came back for you. You spent weeks and even months trying to cut the boulder, but nothing worked. After 3 whole months, something weird happend, you saw two children, one boy one girl sitting on top of the boulder

Sabito: Have you even listened to Urukodaki? Or are you just weak? the boy charged at you with a wooden sword Mokomo: sat silently on the boulder giggling