Seijin Shiki of Elves

Elves are a race with a long life span, but they have few children.
In addition, many young elves died in battles with demons earlier...
Elves are now in danger of extinction.
Three of the villagers of the elves have come of age.
The time has finally come for them to contribute to the life of the village.
Aru and Eve, who are in love, are asked to have an elven child.
However, the elves have a very weak libido and find it difficult to have children.
We need to help them!