Betrayed by the Hero, I Formed a MILF Party with His Mom!

Seres, a magic swordsman who was treated as dead weight in a hero party formed with his childhood friends, is fired one day by the hero and leader, Zect. His childhood friends—the Sword Saint, the Saintess, and the Sage—are all on Zect's side... or rather, they're just harem members. Realizing he is no longer needed, Seres promptly leaves the party. With his S-rank abilities, he could make it anywhere. Thinking he might return to the countryside and take it easy as an adventurer, he stops by a slave market... "No way, Shizuko-san!" "Seres-kun..." There stood the beautiful woman who was Zect's mother and Seres's first love. After rescuing Shizuko, Seres's new adventure begins! The long-awaited book adaptation of the exiled boy's otherworldly mother harem!

Source: Kadokawa, translated