REMAKE・RELIFE 30-SAI NI NARU TO JIYUU NI SEIBETSU TO KARADA WO TSUKURINAOSERU SEKAI NO HANASHI

Remake・Relife 30-sai ni Naru to Jiyuu ni Seibetsu to Karada wo Tsukurinaoseru Sekai no Hanashi summary:

While working on a figure, the sculptor Tominaga Tsukasa longed for the small hands of a woman that could help improve his progress. Because he turned 30, Tsukasa then receives a "Body Remake Application" notification... It seems that recent research has allowed for humans to freely reconstruct (remake) their bodies after the age of 30.
Tsukasa gives it a shot and remakes his entire body to that of a woman's — but after going home — he finds out that his wife Subaru (30) underwent the same procedure and is now a man?! With their minds unchanged and their bodies reversed, the couple begins their second life together!!