From ADV:
Akane is a charming young girl with two separate identities. Growing up as a princess in the Dainagon family, she befriends Aogi, who, as he matures, takes a position with the Inner Guards at the Imperial Palace, thus becoming unavailable to the outside world. When the long-lasting separation from her childhood chum becomes unbearable, Akane must assume a second persona, that of a servant of the Imperial Palace. But entering the gates of the castle doesn't get her any closer to Aogi, and soon, these star-crossed lovers are breaking all the rules for that sweet reunion they both crave.

Based on eponymous video game.

High-school student Kisaragi Maki has one dream: to be a normal wife. She’s part of a Yakuza family known as Group Kisaragi and her father is the third generation of the group - and he wants Maki to be the fourth generation! But Maki isn’t a ‘normal high school student’. She has a split personality which gets her into all sorts of trouble. Can Maki achieve her dream of being a ‘normal wife’?

Kisaragi Maki is the heiress of a yakuza group. She only dreams about being a normal high school student, and becoming an ordinary bride. However, when she sees blood, she changes completely and becomes violent. Will she be able to keep living an ordinary life?