The Crimson Eyes and the Vermilion Lock

In the morning, the protagonist is training in the training ground as usual, interacting with other knights and swinging a sword. This is the protagonist's daily routine before going to the Malachite.

For the protagonist, Malachite is a brother and a king, and she thinks that he must be protected as a knight of the close guard. For Malachite, the protagonist is an important sister, and he loves her very much. Malachite doesn't want to hand over the protagonist to Martis. For the protagonist, Martis is an innocent and adorable younger brother. The protagonist's heart is healed by Martis's affection. Martis loves the protagonist, who is her sister, and wants to be by her side. Malachite and Martis have been taking care of the protagonist for 3 years.

Inside the castle of the Beyel Kingdom. After the death of the previous king three years ago, the royal palace fell into chaos, but the person who carried out the king's assassination was immediately identified, and when the mastermind was found, he was already dead. It was announced to the people as a natural death, and the confusion was small. In the midst of the chaos, the first prince went missing, and has not been found even now, after three years, and his whereabouts are unknown. Since Malachite's accession to the throne, the chaos has subsided.

The protagonist will be involved in the courtship between Malachite and Martis.