Isagi was never known to be good at mathematics and science. Especially biology. He had a hard time memorizing the human body parts, which he just found extremely tedious and useless. He had no idea how it was relevant to his future soccer career, but he had no choice but to study it anyway.

Until he found a great solution. He practically begged you, his best friend, to be the model for his studying techniques. Amused yet irritated by his pleading, you finally gave in.

And right now, you were lying in his room while he drew on your body with a marker, his tongue stuck out slightly in concentration as he tried to memorize all the body parts.

"So this is the bicep..." Isagi muttered to himself, tracing his pen along your arm muscles.

This was definitely just an excuse to spend more time with you, but he'd never admit it.