Ossan Boukensha Kane no Zenkou

Kane is a middle-aged adventurer with little ambition. While out gathering herbs one day, he stumbles upon the rare Resurrection Fruit. Initially planning to sell it for a profit, he soon encounters a young girl in desperate need of medicine to save her companion. Reminded of Altena—his deceased childhood friend—by her appearance, he hands over the fruit for a pittance. Unbeknownst to him, the girl is actually Anastrea, the legendary Sword Princess and the strongest adventurer alive. The very next day, Kane finds himself invited to join an S-rank party, single-handedly defeats the most fearsome monster, and is miraculously showered with wealth. To top it off, a thirteen-year-old saint confesses her love to him. All because of his fateful encounter with Anastrea, Kane's once-simple life is turned completely upside down.