My first attempt at writing Rikkai, so forgive any poor characterizations. You can choose to read it as gen or Marui/Kirihara, which is what I had in mind when I wrote it.
"Marui-senpai, you're heavy. Get off!" Kirihara squirmed as he lay pinned to the floor of the clubroom. "Buchou, can't you tell him to get off me?!"
Yukimura sighed. It was already like this, even though he had only been back at school for a week. Sanada was nowhere to be seen, risking laps in exchange for not having to deal with this ...incident. Perhaps he was already doing laps. If he wasn't, he would be soon, or maybe Yukimura would just assign him to the first years for the next week.
"Bunta." Yukimura finally decided to intervene, despite his initial reluctance. "Why are you sitting on Akaya?"
Marui glanced up at the other boy, who had walked over next to them. "He ate my Valentine's Day chocolate."
Yukimura just stared at him. He sighed again before turning around. He picked up his racquet that was leaning against his locker and walked toward the clubroom door.
"Buchou!!!" Yukimura paused slightly at the entrance to the room. 'Really, that squeal was far too feminine for Akaya. And it's not like this is new for him.'
"Bunta, I'll let you punish him, but make sure you're both out on the courts in 15 minutes."
"Right." Marui saluted as Yukimura exited and smirked down at a now cowering Kirihara. "You heard buchou; you're mine for the next 15 minutes."
Yukimura was standing just outside the clubroom when he heard another squeal. Glancing at his stopwatch, he set off in search of Sanada, who was definitely in for his own punishment as well.