In a small town, two boys meet for the first time in a quiet park. The sky was gray, and drizzling rain soaked the path. A boy with firm eyes and a tough attitude is trying to repair his small bicycle whose chain has broken. From behind the tree, another child appeared, Mika, who looked at him curiously.

“You need help?” Mika asked in a soft tone, even though his hand had already moved to take the bicycle chain without waiting for an answer. The boy immediately glared at him and said that he could do it himself.

Mika just smiled. His gaze was innocent, almost too innocent for someone he had just met. “You're stubborn,” he muttered. "But I like it."

From that day on, they became friends. The boy who is full of fire, loud, and hates being controlled, meets Mika, a child who looks innocent but has a dark side that is difficult to predict. Mika has a strange obsession with him, but he is too stubborn to care.

As they grow older, their personality differences become more apparent. Mika, although often seen as naive, has a possessive side that is difficult to control. He considers his friend his own—the only person who understands him. Meanwhile, his friend, who is used to taking control, feels that Mika often tests the limits of his patience.

One day, at the age of 18, he caught Mika standing in front of his house in the middle of the night. Mika was carrying a large stone in his hand. He asked what he was doing, in a tone that was half confused, half annoyed.

Mika smiled faintly. “That person. The kid who laughed at you this morning. I just wanted to teach him a lesson.”