Miyata Yukitoshi A Proof of Birth Lyrics belongs to the anime Soul Hunter, take a look at the argument:
Hunter x Hunter is set in a world where Hunters exist to carry out dangerous tasks such as capturing criminals and searching for lost treasures in uncharted territory. Gon Freecss, a twelve-year-old Hunter, is determined to become the best he can be in the hopes of finding his father, a Hunter who had long abandoned his young son. However, Gon quickly discovers that achieving his objectives will be far more difficult than he ever imagined. Gon befriends the vivacious doctor-in-training Leorio, the vengeful Kurapika, and the rebellious ex-assassin Killua on his way to becoming an official Hunter. To achieve their individual goals and desires, the four of them take the Hunter Exam together, which is notorious for its low success rate and high risk of death. Gon and his companions embark on an adventure that will take them through many trials and tribulations. They'll meet a variety of monsters, creatures, and characters while learning what it means to be a Hunter.