The Unbeatable Magician (E04)

Until the age of 16, Yang Wen-li spent most of his life on an interplanatary merchant spaceship with his father, who was a trader. After his father's death, Yang entered the Free Planets Fleet Academy to study war history. There, he met Jean, who would become his best friend, and his childhood friend Jessica, a music school student. (Crunchyroll)