Wasurerareshi no Eiyuutan: Seiyuujo Party ni Yasashiki Tsuihou wo Sareta Otoko wa, Kioku ni Nokorazutomo Kanojo-tachi wo Sukuu

This is a story of bonds and memories, of a man who believed in bonds and continued to care for his comrades.

Kazuto, a boy transported to Fernad, a world of swords and magic.
As a price for the power bestowed upon him by the Goddess of Bonds, he acts as a "Lost Namer," disappearing from the memories of those he comes into contact with when he leaves his party.

Kazuto survives countless adventures and becomes a member of the S-rank Saint Brave Maiden Party. But just before the final battle with the Demon King, he is expelled from the party by the Saint Brave Maiden Romina, and disappears from their memories.

Six months later, he hears the good news that the Demon King has been successfully defeated by Romina and her friends.

Kazuto, who had been traveling alone as a mere adventurer, returns to town after the battle.
His heart is always with them.

(Source: Akita Shoten, translated)