The Ossan Newbie Adventurer, Trained to Death by the Most Powerful Party, Became Invincible

"Why should it matter how old you are if you want to start something new?" The strongest guy around, who also happens to be middle-aged, strives to be an adventurer! Everyone seems to think you should pursue your dreams while you're still young, but there's one man who just can't give up. In a worl...