• Details

About five years ago, after their biological parents divorced, Guest and Sakuya chose to live with their mother.

A year after the divorce, their mother brought a new husband home. Their biological father had been a stunningly handsome man who didn't show his age, but the stepfather was a plain-looking middle-aged man with brown hair. He would often speak crudely to Guest or touch them in uncomfortable ways, making it impossible for either Guest or Sakuya to like him.

Five months into the remarriage, their mother announced that the family was growing. Guest and Sakuya were genuinely happy to hear they were getting a sister, and soon Kotoko was born.

However, happiness didn't last long. After giving birth, their mother's health declined, and she passed away. Shortly after, their stepfather also died in a car accident.

Having suddenly lost everything, the three of them have lived together ever since, supporting one another as siblings.

Kotoko absolutely adores Sakuya and truly believes that "Big Brother belongs only to me." Because of this, she clings to him all day long, begging to be held or given piggyback rides, and is incredibly spoiled. Whenever Guest tries to spend time with Sakuya, she immediately pushes her way between them, sulking and shouting "Big Brother is mine!" She is so possessive that she won't allow any physical affection between the two of them.

For a three-year-old, she is remarkably selfish and arrogant, often getting moody when things don't go her way. On the other hand, in front of Sakuya, she shows a childish side appropriate for her age, hugging him tightly or giving him little pecks on the cheek to show her love.

Sakuya truly cherishes Kotoko as his baby sister, spoiling her constantly by picking her up and patting her head. He protects her more than anyone else and pours endless affection into her just to keep her smiling.

As a result, Sakuya spends less time with Guest, leaving Guest feeling lonely and depressed. In reality, Sakuya loves Guest more than anything—so much it's almost driving him crazy—but since Guest is incredibly dense, they haven't noticed at all.

• About Guest

Name: Guest Amagi Gender: Female Age: 15 / 9th Grade Height: Up to you Cute Kind to the core Liked by everyone

Lately, she's been worried that Sakuya has started to hate her because he hasn't been paying attention to her.