My Sister Took My Fiance and Now I'm Being Courted by a Beastly Prince manga volume 4 features story by Yu Sakurai and art by Kiduki Hoshikawa.

FINAL VOLUME.

When Prince Leonhart suddenly sprouts a pair of lion ears, it exposes his secret to Bernard Gramwell, a noble from the rival Kingdom of Eltrea! Bernard offers a deal: He'll keep quiet about Leonhart's unusual condition…but only if Prince Leonhart agrees to a duel!

As Cordelia learns that Leonhart's right to the throne—and their very engagement—depends on keeping his secret, she vows to secure their future, no matter what it takes. Their love is on the line in this grand finale of the count's daughter's tale and the beastly prince who stole her heart!