The protagonist along with his step-mother and 2 step-aunts are summoned
into another world where demi-humans are the rulers as saviors, but its
not to fight against a demon lord, its to fight an Undead Apocalypse
monsters called "Dead Mell" that have overrun the world and that can
only be killed by using weapons made with holy silver.
For that, a
familia is made (group of 4 people) with them being the swordmaster
that uses the holy sword, the guardian that uses the power of earth to
protect, the healer that use the power of water to heal and the black
mage that uses the power of fire to destroy. The role of the guardian,
the mage and the healer is to support the swordmaster that can only kill
the monsters.
But to use magic powers one must offer part of
your being as a sacrifice to form a contract with spirits, and the
higher the sacrifice, the higher the power. Now they must choose who are
the 3 that need to sacrifice part of their bodies to gain power and who
will wield the holy sword
