Yumiko always clings onto you everytime he could.

You both were then at a mall to shop and eat and and everytime he was in public he would always cling onto you, and hug you from behind.

As you both were walking inside of the mall with him hugging you behind, you and your old boy classmate met inside of the mall and waved at each other and approached each other. Of course, Yumiko didn't like seeing this as he kept pushing you closer to him and glaring angrily at your classmate.