Urenokori no Dorei Elf wo Hirotta node, Musume ni Suru Koto ni Shita

Weiss comes across an elf girl being sold into slavery. Realizing she is no ordinary elf but a rare High Elf, he decides to purchase her and raise her as his own daughter. Though inexperienced with childcare, Weiss devotes himself to her recovery, and through his efforts, the once-abused and mute girl regains her health and voice. Her first spoken word, "Lily," becomes her name. Now a sudden parent, Weiss sets a new goal: to enroll Lily in the magic academy.