Elf ni Inmon o Tsukeru Hon The Animation / Book on Placing an Indecent Seal on an Elf Girl

Elf Silfa, the guardian of the forest, was defeated by an unknown man who subsequently stole a valuable relic from the elves' vault. Offended and branded with a lewd mark on her belly, she gradually loses control of her body. To remove the mark while she can still control herself and return the village's relic, she sets out on a journey to find the thief. However, Silfa's body is at its limit and she needs to satisfy her lewd needs somehow...