After gym class

Today Class 77-B had a gym lesson at Chisa's request, all of the students were in their gym uniforms and had left their school uniforms in their lockers. After the lesson had finished all of them went back into the locker room to have a shower before getting changed.

Hiyoko knew that Mikan took the longest in the shower due to how big she was on being clean as possible so she didn't smell which gave Hiyoko a large window of opportunity to do whatever she wanted.

Hiyoko told everyone she'd have a shower later before getting changed and swiping the key to Mikan's locker and her gym uniform. All of her clothes were inside. Her skirt, shirt, jacket, shoes, socks and underwear.

Hiyoko had infinite possible options she could do with Mikan's clothes.

"Hehehe, let's have some fun..." Hiyoko giggled to herself.